## Why
Paste placeholders and deferred slash-command parsing can hide the meaning of an input until it is expanded or a session is configured. Draining such input as an ordinary message can accidentally treat pasted text beginning with `!` as a shell command or lose `/plan` behavior.
## What changed
- Track paste-expanded inputs that begin with `!` as literal model input through history, queue editing, retries, and startup queues.
- Defer `/plan` parsing when session or model state is unavailable, then submit it in plan mode with shell escapes disabled.
- Drain queued input only after session configuration, and keep later queued prompts pending when an initial prompt cannot be submitted.
- Suppress queue auto-send before applying a replayed thread session so input from the outgoing thread is not submitted during restoration.
## Testing
Add coverage for direct, recalled, edited, interrupted, rejected, startup-queued, and plan-mode paste flows, including placeholder collisions and rejected initial images.
GitOrigin-RevId: d482220d8df21754f166fea5b54e9945f622a978
Eric Traut
3434c2545b