## What changed
- Add `codex-utils-audio` as a workspace crate for canonicalizing audio inputs
and estimating their token usage.
- Update `codex-core` to consume the new crate while preserving the existing
audio preparation tests.
GitOrigin-RevId: d719ecc08363ef52778aa37f3df0ca14f7778324
## What changed
- Track approved command prefixes separately from the stable permissions
instructions in world-state snapshots.
- Emit only newly approved prefixes after an exec-policy amendment instead of
appending the full permissions block again.
- Preserve prefix updates when full permissions instructions are disabled and
remain compatible with legacy world-state snapshots.
## Testing
- Cover incremental prefix additions, removals, legacy snapshots, history
rollback, and approval flows with permissions instructions enabled or disabled.
GitOrigin-RevId: e6f68c6a91be82750e70e28456f2b7c58607fbd8
## What changed
- Add `include_plugin_usage_instructions` to model metadata, defaulting to false.
- Emit generic plugin guidance only when plugins are available and the selected model enables it.
- Enable the capability for interactive model presets while leaving `codex-auto-review` opted out.
GitOrigin-RevId: 67f5a97e978033f5f1d533956c0b9deeae610283
## What changed
- Remove `ModelInfo.base_instructions` as an in-memory instruction source and use `model_messages.instructions_template` consistently for bundled, remote, fallback, and overridden model metadata.
- Preserve compatibility by promoting legacy `base_instructions` values when reading model responses and caches, and by including rendered legacy instructions when serializing `ModelsResponse` for older clients.
- Treat templates without instruction variables as literal text and retain the other model-message fields when applying instruction overrides.
This completes the consolidation proposed in https://github.com/openai/codex/pull/31302.
## Testing
- Cover legacy response and cache migration, canonical-template precedence, fallback instructions, personality rendering, overrides, and model switching.
GitOrigin-RevId: 089d986ca5e30da67db2c77a1b6a046d2cff52dc
## Why
MCP tools can be exposed directly, discovered through tool search, or called
from Code Mode. Servers need to be able to opt out of any of these surfaces
without disabling their tools everywhere.
## What changed
- Add `omit_tools_from` to MCP server configuration, accepting any combination
of `direct`, `deferred`, and `code_mode`.
- Apply the exclusions independently when building direct, deferred, and Code
Mode tool surfaces while keeping omitted tools registered for permitted uses.
- Remove client-private `_meta` fields from MCP results returned to Code Mode.
- Include the new setting in the configuration schema and MCP config
serialization.
## Testing
- Cover every exposure combination across Code Mode, Code-Mode-only sessions,
tool search, direct-only namespaces, and prefixed and unprefixed MCP names.
- Verify direct and nested execution paths, parallel-call support, config
round-tripping, and `_meta` filtering.
GitOrigin-RevId: 12dfcb78bb5c5ecf4d70f38a8b5022792463a27f
## What changed
- Replace the ordering enum and `include_disabled` boolean with named
`ConfigLayerStack` iterators for each precedence direction.
- Keep enabled-only iteration separate from `all_layers_*` iteration, which
includes disabled layers.
- Update config consumers to use the iterator matching their precedence and
disabled-layer requirements without allocating an intermediate `Vec`.
## Testing
- Add coverage that verifies ordering and disabled-layer filtering for all four
iterators.
GitOrigin-RevId: d14df3db4a2eae80ba97cdec246bff405e6c5f3d
## What changed
Derive code-mode tool names directly from registered tool names when checking
eligibility and collisions. Skip unsupported and empty tool specs explicitly,
without serializing schemas or augmenting descriptions that are not used during
executor registration.
GitOrigin-RevId: b439327aafd85ce3745d900301b7e48b56dbd6b4
## What changed
- Route verified patches from both direct tool calls and intercepted shell commands through a shared execution helper.
- Simplify patch safety preparation to return either a runtime invocation or a rejection directly.
- Keep permission resolution, approval handling, event emission, runtime execution, and diff tracking in the common path.
GitOrigin-RevId: e16aae8e91d96b8108aefac7f3fbf2da2cbac016
## What changed
Replace the type-erased `FragmentRegistration` trait and proxy objects with a
static list of `matches_text` function pointers. Remove the registration types
and their re-exports while preserving the existing contextual fragment matchers.
GitOrigin-RevId: 4e5a296b278984c6e783a67f48fa4bb37646946b
## What changed
- Store each turn's host skills snapshot in `ExtensionData` and expose it through
`TurnContext::skills_snapshot`.
- Lazily keep implicit skill invocation deduplication state in the same turn-scoped
store.
- Carry the skills snapshot into review turns without a separate
`TurnSkillsContext` field.
GitOrigin-RevId: d71579b5d230bd0b5f3c2ad062861f74d614d88c
## What changed
- Share argument normalization, server selection, cursor validation, and pagination setup between `list_mcp_resources` and `list_mcp_resource_templates`.
- Use a generic server-tagged wrapper to build single-server and deterministically sorted all-server payloads for both resources and templates.
## Testing
- Cover shared argument normalization and sorted resource-template payload serialization.
GitOrigin-RevId: 3505e4c1d2b95d8bbbb01f6f930fb914309eb898
## What changed
- Emit dynamic tool-call analytics for code mode `exec` and `wait` calls, including duration and terminal status.
- Associate code-mode cells and their nested tool calls with the originating and subsequent model response IDs.
- Buffer correlated tool events until the next response is known, while flushing pending events when turns, threads, or the analytics queue close.
## Testing
- Add reducer coverage for correlating `exec`, `wait`, and nested tool events across turns.
- Add an app-server test that verifies production analytics include the cell and response IDs for a code-mode `exec` call.
GitOrigin-RevId: 8b34ab59c1ad68ebbd57f9c8a05f19ab04df48a4
## What changed
- Store synchronization primitives directly in `TurnMetadataState` instead of
wrapping each field in its own `Arc`.
- Require an `Arc<TurnMetadataState>` when spawning Git enrichment so the
background task retains the complete state.
- Update Git enrichment tests to use the shared state container.
GitOrigin-RevId: 745ca6504c0a6533cb7726d045905472e51726df
## What changed
- Add a shared runner for MCP resource operation lifecycle events, output serialization, truncation, timing, and error handling.
- Use it for listing resources, listing resource templates, and reading resources.
GitOrigin-RevId: 84cae2e01a096d5b8ed97ea1cb462f01fe2ed1f9
## What changed
- Charge `codex_rollout_budget_units` against the shared rollout budget when the provider includes it in response usage.
- Fall back to weighted input and output token accounting when provider units are absent.
- Reject non-finite or negative provider units as a fatal response error.
## Testing
- Cover provider units in reminder thresholds and local and remote compaction budget exhaustion.
- Verify invalid units fail without retrying the response.
GitOrigin-RevId: b452403e365985854d16f298d1ba46383e9892c4
## What changed
- Parse `codex_rollout_budget_units` from completed Responses API usage into
`TokenUsage`.
- Keep the provider-only value out of serialized protocol, JSON schema, and
TypeScript representations.
## Testing
- Cover the value in unit and end-to-end SSE response parsing tests.
GitOrigin-RevId: a53d4202beb9c8985d25894cb10e7c01f20b2a44
## What changed
- Reattach recorded `executed_tool_calls` metadata when an output is included in a subsequent prompt.
- Bound retained metadata to 32 KiB, prioritizing recent calls and reporting omitted calls in truncation metadata.
- Drop retained entries after their corresponding outputs leave the prompt history.
## Testing
- Cover metadata replay, cleanup after compaction, bounded retained history, and propagation through later tool requests.
GitOrigin-RevId: 1c23a26123be3b7ad51c61f4ad522139b71bb773
## What changed
- Add the optional `delegationAckFiller` field to `thread/realtime/start`.
- Forward explicit `true` or `false` values to V3 Frameless Bidi session payloads as `delegation.ack_filler`; leave the field absent when unspecified so the Realtime API default is preserved.
- Document that V1 and V2 ignore this setting.
## Testing
- Cover both boolean values in Frameless Bidi serialization and verify the WebRTC V3 session creation payload.
GitOrigin-RevId: 9fe8efd14e42738c3e86e3e9a8af81d0f4521244
## Why
Clients need to know whether a `request_user_input` request must wait for an
explicit response or may auto-resolve. Using `autoResolutionMs` as that signal
conflated the blocking decision with timeout policy.
## What changed
- Add required `isBlocking` fields to user input protocol and app-server
request payloads. Plan-mode requests are blocking, while requests from other
enabled modes are non-blocking.
- Drive the TUI's auto-resolution behavior from `isBlocking` and remove
`autoResolutionMs` from the model-facing tool schema.
- Deprecate `autoResolutionMs` while retaining it for compatibility, and treat
legacy payloads without `isBlocking` as blocking.
## Testing
- Cover mode-derived blocking behavior, legacy deserialization, app-server
forwarding, delegated requests, and TUI auto-resolution.
GitOrigin-RevId: 29aade657ef743065ec264376ba567a9b353d7d7
## What changed
- Add optional `realtimeStartInstructions` and `realtimeEndInstructions` fields to `thread/realtime/start`.
- Apply the instructions when Codex enters and leaves realtime mode, while preserving the existing defaults when either field is omitted.
- Limit each field to 8,192 estimated tokens.
## Testing
- Cover custom entry and exit instructions across realtime state transitions.
- Cover token-limit validation for both fields.
GitOrigin-RevId: b9cfa1ff22e084d8a6b2ed56bd27d95ffdd6b6bd
## What changed
- Record the effective detail setting and source and prepared dimensions for
successfully decoded images.
- Associate message images with their role and tool-output images with their
originating call ID.
- Include the collected image preparation metadata in the corresponding turn
analytics event.
## Testing
- Cover image resize metadata, tool-output attribution, turn aggregation, event
serialization, and app-server analytics output.
GitOrigin-RevId: dbfb5ba1ce7cb02dd93d9b579c5109817f16aef5
## What changed
- Add `CodexThread::submit_user_input_and_wait_for_admission` and export the
`UserMessageAdmission` result through `codex-core-api`.
- Resolve submissions only after they start a new turn or steer the active
turn, returning the accepting turn ID in either case.
- Return errors for invalid operations, rejected thread settings, and session
termination instead of leaving admission waiters unresolved.
## Testing
Add integration coverage for concurrent start-and-steer submissions, settings
rejection and recovery, non-user operations, and submission after shutdown.
GitOrigin-RevId: 21f1ede38d399baa9836d61a59b9f9af2dbf83b8
## Why
`ToolExecutor::exposure()` describes a tool's preferred exposure, while the host
may apply step-specific policy when building a tool plan.
## What changed
- Store each runtime together with its effective exposure in `ToolRegistry`.
- Apply MCP, namespace, and collaboration-tool exposure overrides directly to
registry entries instead of wrapping runtimes.
- Use the registry-owned exposure when building model-visible specs, deferred
tool search, code-mode executors, and parallel-call support.
## Testing
- Cover that a hidden MCP tool remains routable but is not eligible for parallel
tool calls.
GitOrigin-RevId: 1bc2760add8d993f477954269fa13681bfcc2444
## What changed
- Recognize the `codex_strict_auto_review` MCP elicitation marker and route
marked approval requests through the configured automatic reviewer.
- Accept only canonical automatic-review approvals and fail closed without a
user prompt when review is unavailable, denied, malformed, disallowed by
policy, or requests persistence.
- Validate Codex Apps approval metadata against the active MCP invocation and
build the review request from the trusted invocation details.
## Testing
- Add unit coverage for strict review decisions, malformed markers, reviewer
failures, explicit policy denials, and lifecycle cleanup.
- Add app-server round-trip coverage for approvals, denials, configuration
constraints, spoofed metadata, persistent requests, and subsequent turns.
GitOrigin-RevId: af73b45a9b63118f25f6429d95b3222c5dbb59fb
## What changed
- Make the skills extension own the catalog prompt templates and rendering path.
- Remove the duplicate core fallback that injected available skills into initial context.
- Update core integration tests to install the skills extension explicitly when they expect model-visible skill context.
GitOrigin-RevId: bbe6b15c4e776a09c98b7f4166426fe4e58434ba
## What changed
- Read the frozen MCP tool catalog directly from the step-scoped `McpBinding`
when building tool routers, plugin injections, and connector state.
- Remove the redundant `Vec<ToolInfo>` from `StepContext` and stop returning a
duplicate catalog from `built_tools`.
GitOrigin-RevId: d12d694e1224da3f6ccb1960868491f0d80c6e19
## What changed
- Route skill dependency updates through the shared `codex-core` `ConfigEditsBuilder`.
- Remove the duplicate MCP config writer and its tests from `codex-config`, while retaining MCP config loading there.
GitOrigin-RevId: cdce84c8353514529126156750433e859b78be3b
## Why
Tool calls can outlive the sampling request that advertised them, so execution
must retain the finalized tool plan for that specific step.
## What changed
- Resolve tool runtimes, parallelism, cancellation behavior, argument diff
consumers, and dispatch from the `ToolRouter` stored in `StepContext`.
- Remove the separate router parameter from `ToolCallRuntime` and code-mode
worker construction so callers cannot supply a different router.
- Add a test helper for installing a router into a test `StepContext`.
GitOrigin-RevId: 9e476ddd228ca5b1c03ed87863618ba77de6200c
## Why
Threads can configure the same MCP server name with different runtimes. Tool calls
must use the runtime associated with the thread that issued the call.
## What changed
- Route MCP readiness checks and call preparation through the invoking session.
- Add regression coverage that alternates calls between two threads and verifies
that each thread continues using its own MCP server process and configuration.
GitOrigin-RevId: 5735f7b29a579f545351385ab01a575e35ead01e
## What changed
- Replace `SessionTaskContext` with `Arc<Session>` in the session task run and abort interfaces.
- Read extension data from `TurnContext` during regular turns instead of storing and forwarding a duplicate reference through the running task.
GitOrigin-RevId: 04bc0d324e5ba781f35ac9c61e811888208b74ae
## What changed
- Add optional `default` and `plan` collaboration-mode messages to model catalog metadata.
- Prefer the active mode's catalog message, including an explicit empty value, while falling back to the existing developer instructions when the catalog variant is absent.
- Track the model in collaboration-mode world state so mode and model changes append the appropriate instructions, and clear prior instructions when no current message exists.
- Preserve catalog collaboration messages when instruction overrides remove other model instruction fields.
## Testing
- Cover catalog deserialization, variant selection, fallback and empty-message behavior, legacy snapshot migration, mode changes, and model changes.
GitOrigin-RevId: d4c6c0028423bc50b0e8175e55586f3e7bc1c3a8
## What changed
Reject `shell_command` and unified `exec_command` calls that provide a
`justification` without also specifying `sandbox_permissions`. The
model-visible error tells callers to explicitly request `require_escalated`
execution or omit the justification.
## Testing
- Add unit coverage for `shell_command` argument validation.
- Add integration coverage for both shell tool paths, including verification
that rejected unified exec calls do not begin execution.
GitOrigin-RevId: 6af39d2c889af492440615eae12085b99a8b5169
## What changed
- Register the legacy `shell_command` handler only when exactly one local environment is available, including when unified exec keeps it hidden for compatibility.
- Reserve the unnamespaced `shell_command` name so external tools cannot claim it when the built-in handler is unavailable. Namespaced tools with that name remain supported.
## Testing
- Cover remote and multiple-environment tool plans, unified exec routing, and external tool registration for reserved and namespaced variants.
GitOrigin-RevId: 93834539b31ac8a7fea072bfa4de792bcc3e053b
## Why
MCP servers running in an executor must not reuse host-owned OAuth credentials,
even when they have the same configured server name and URL.
## What changed
- Derive environment-scoped credential names for executor-owned MCP servers and
use them consistently for login, logout, authentication, and connection setup.
- Mark executor-owned entries in the file credential store and fail closed when
loading or saving an entry could cross the host/executor boundary.
- Preserve compatibility with existing local OAuth credentials, including local
server names that overlap the new reserved prefixes.
## Testing
- Extend the executor MCP integration test to verify that executor requests use
the executor token, never send the host token, and persist both credentials
separately.
GitOrigin-RevId: 4fc92d0533b0fe2e0df34f6d47b81e3d20d07807
## What changed
- Move the V8 implementation into a dedicated `codex-code-mode-runtime` crate used by `codex-code-mode-host`, removing the embedded runtime fallback from the Codex process.
- Resolve the host executable from the active installation layout and check its availability before selecting tools.
- Fall back to direct tools with a one-time warning when optional code mode is unavailable. Keep `code_mode_only` and `disable_in_process_fallback` configurations fail-closed.
## Testing
- Cover host discovery for standalone and package layouts, including missing hosts and symlinks.
- Verify direct-tool fallback, one-time warnings, and fail-closed code-mode-only behavior.
GitOrigin-RevId: 5aa3c6f1db148b2231fc24089a2ee0e2b00dbddb
## Why
Filesystem denials and managed-network blocks did not share a structured event
shape, requiring downstream consumers to rediscover enforcement paths and parse
backend-specific output. See https://github.com/openai/codex/pull/17573.
## What changed
- Add normalized filesystem and network violation types in `codex-sandboxing`
and emit them through a shared tracing seam.
- Classify filesystem denials by backend and reason, retaining an optional path
and bounded output snippet, and preserve managed-network block context.
- Report the sandbox type through exec-server responses so unified exec can
classify remote denials without guessing; omitted values remain compatible
with older peers.
- Record violations from exec, apply-patch, shell-escalation, unified-exec, and
managed-network enforcement paths without changing denial behavior.
## Testing
- Cover filesystem classification, path extraction, `SIGSYS`, network event
conversion, protocol compatibility, and remote sandbox-type propagation.
GitOrigin-RevId: d673173b4fa6bdf0a24421194a8a61c81fab9c96
## Why
Removing each decoded prefix from a `Vec` shifts all remaining bytes. Repeating
that work is costly for streams containing many invalid UTF-8 bytes or many
framed messages in one relay record.
## What changed
- Buffer unified exec output in a `VecDeque` and use UTF-8 error offsets to
consume the largest valid prefix while continuing to make progress on invalid
input.
- Buffer Noise relay messages in `BytesMut` and advance past decoded frames
without moving the remaining bytes.
## Testing
Added regression coverage for valid data surrounding invalid UTF-8, front
consumption without shifting, and reassembling many JSON-RPC messages from one
record.
GitOrigin-RevId: 661ccfffc68960ac6c9d37c738224da8ea83cbf0
## Why
The `<current_date>` in environment context could diverge from the clock used by current-time features, especially when a host provides an external clock.
## What changed
- Read the current time from the session's time provider whenever world state is built, and render its local date in environment context.
- Use each session's own thread ID for clock reads, including guardian sessions.
- Propagate clock-read failures through turn error events and stop before model inference.
## Testing
- Cover date updates across turns and app-server requests.
- Verify guardian clock reads use the corresponding root or guardian thread ID and do not run during prewarm.
- Verify clock failures emit an error without sending an inference request.
GitOrigin-RevId: bb7f32ccc0229b7bc6f14d7356db00bcce78066d
## What changed
- Pass the canonical `PermissionProfile` through execution requests, sandbox
selection, escalation, and the exec server instead of carrying separate
derived filesystem and network policies.
- Derive runtime sandbox policies from the effective profile at their points of
use, including after applying additional permissions.
- Update sandbox and escalation tests to inspect policies through the profile.
GitOrigin-RevId: 695b82ea94f5289516b0933bb23074cb2dcce8ac
## What changed
- Add the opt-in `executed_tool_call_metadata` feature to record model-attempted direct and code-mode tool calls.
- Attach recorded names and arguments to the matching tool output in the next Responses request, preserving the metadata across sampling retries.
- Bound pending calls and argument sizes, and emit truncation metadata when limits are exceeded.
## Testing
- Cover disabled-by-default behavior, namespaced and nested calls, blocked or failed attempts, retry handling, and recorder limits.
GitOrigin-RevId: 5ce917b73e797b0f6904d46477b9d2cf8ea71bf2
## What changed
Return telemetry tags directly from `CoreToolRuntime::telemetry_tags` instead of
wrapping them in a future, and update the MCP runtime and tool registry call site
accordingly.
GitOrigin-RevId: 54e03972fe23c0e644c68c73af504dba0871be8e
## What changed
Build the `apply_patch` filesystem sandbox context from the executor's canonical permission profile instead of the execution attempt's materialized profile. Continue merging any additional permissions requested by the patch while keeping workspace roots scoped separately to the attempt.
## Testing
- Update the sandbox-context test to verify that executor `workspace-write` permissions are preserved when attempt workspace roots and additional file permissions are present.
GitOrigin-RevId: 2a9a8c2e1b1945e300283c400d0f1e573225a553
## What changed
- Track the first registered tool for each normalized code-mode identifier and use that tool consistently for dispatch metadata and model-facing code-mode declarations.
- Skip duplicate normalized names when building the code-mode executor while preserving shadowed tools in the registry and direct tool exposure where applicable.
- Cover collisions across dynamic and namespaced tools, direct and deferred exposure, code-mode-only operation, and Responses Lite metadata.
GitOrigin-RevId: a4acb57ce44e7de1398981b22af4b87e2a35870f
## What changed
- Retain bounded, non-completion agent messages in remote v2 compaction history so delegated tasks remain available on follow-up turns.
- Account for encrypted agent-message content when estimating token usage and place restored initial context before the latest real user or agent message.
- Exclude child completion messages from retained follow-up history and strip inherited parent agent messages when forking a child.
## Testing
- Extend compaction, history-estimation, and agent-fork tests to cover encrypted delegated tasks, child completions, context ordering, and fork sanitization.
GitOrigin-RevId: ba4392e9cfdf4ecbcdc9c7d8581d58a8d2d78260
## Why
External MCP, extension, and dynamic tools can collide with host-owned tool
names. In particular, a dynamic `tool_search` definition must not replace the
host implementation used to discover and route deferred tools.
## What changed
- Build each turn's tools through a single ordered `ToolRegistry` that retains
the first runtime registered for a name.
- Treat duplicate external tools as skippable collisions while preserving
strict duplicate checks for trusted host tools.
- Reserve host-owned code-mode and `tool_search` runtimes before producing the
model-visible tool list.
- Base hosted web-search fallback behavior on the extension runtime that
actually won registration.
## Testing
- Cover ordered registry mutation and duplicate handling.
- Verify a client-provided `tool_search` cannot shadow the host tool.
- Verify hosted web-search fallback follows the registered browser runtime.
GitOrigin-RevId: acebe360de8ec69ad7da2f684cc2542cbf18a984
## Why
Executor capability discovery can traverse plugin and skill roots, including
symlinks. Under restricted filesystem permissions, discovery must not expose
files outside the permitted paths.
## What changed
- Pass each environment's filesystem sandbox context through capability root
discovery and apply it to metadata, directory walks, and file reads.
- Enable discovery for restricted sessions so permitted executor skills remain
available while inaccessible roots and symlink targets are omitted.
- Key discovery caches by sandbox context and reject sandboxed discovery on
executors that do not advertise support for it.
- Split requests with more than 128 roots into supported-size batches.
## Testing
- Cover permitted and denied external symlink targets.
- Verify restricted skill listing excludes inaccessible skills.
- Verify cache separation across permission contexts and discovery of 129 roots.
GitOrigin-RevId: 44d16468ca003403bdb8b71a04ae8c9ff94ed494
## Why
Executor-backed skill resources must honor the active filesystem permission profile instead of reading outside its allowed roots.
## What changed
- Propagate each environment's filesystem sandbox context into `skills.read` calls.
- Apply turn-scoped permission grants when reading executor skill resources.
- Fail closed when no matching sandbox context exists or a restricted Windows read cannot be sandboxed.
- Preserve the existing resource size limit for both sandboxed and streamed reads.
## Testing
- Cover reads within permitted roots and reads that succeed after a permission grant.
- Verify denied references do not expose their contents and disabled Windows sandboxing is rejected.
GitOrigin-RevId: 5cc679b9385b0621665ff20cf5848863cc6396a4
## What changed
- Add an optional `wait_until_ready` hook to `CoreToolRuntime` and invoke it
before acquiring the tool execution gate.
- Move MCP refresh and server-startup waiting into the MCP runtime's hook.
- Forward readiness waits through tool exposure and namespace wrappers.
- Test exact runtime selection for plain and namespaced tools, including
exposure overrides and missing tools.
GitOrigin-RevId: 8718589fa06f14d053a35a288186613f649d25ff
## What changed
- Split core tool planning from the assembly of MCP, extension, and dynamic tool runtimes.
- Build `ToolRouter` from a single ordered runtime list plus hosted tool specs.
- Centralize whether each `ToolExposure` variant is available in code mode.
- Preserve core, MCP, extension, and dynamic source ordering and existing name-collision priority.
## Testing
- Add coverage for unified source ordering and collisions, code-mode exposure, and standalone web search alongside MCP and dynamic `web.run` tools.
GitOrigin-RevId: b010c2e9728b92b75a35325ca9b2ec465c3bac12
## Why
`codex-http-client` is the intended owner of `reqwest`, while direct first-party
dependencies are tracked as migration debt.
## What changed
- Use `http` header and status types directly in core code and tests.
- Build the MCP test readiness client through `HttpClientBuilder`.
- Remove `reqwest` from `codex-core` and its temporary dependency-policy
exception.
GitOrigin-RevId: 8d5c7c86256294a7bb8aa1ae10cc5bea4cb1fc56
