feat(worker): add gitea activity feed poller

Hits /api/v1/users/{user}/activities/feeds?only-performed-by=true
on the configured gitea host (default git.lair.cafe). Page-1 polling
on a 10-min cadence; first run paginates back through up to 20
pages (1000 items) to seed history.

Gitea has no ETag support on this endpoint, so each tick is a fresh
fetch — relying on idempotent upsert by `gitea:<id>` for dedup.

Reshape covers the gitea op_type set:
  commit_repo  → "pushed N commits to repo:branch" + commits body,
                  parsing the JSON-encoded `content` field
  push_tag     → "tagged X in repo"
  create_repo  → "created repo"
  rename/transfer/delete_branch/delete_tag/star/fork — straightforward
  create/close/reopen_issue        → "{verb} issue #N in repo: title"
  create/close/reopen_pull_request → "{verb} pull request #N"
  merge_pull_request               → GitMerge icon
  comment_issue, comment_pull      → markdown body from comment.body
  approve/reject_pull_request, publish_release
  fallback for anything else (mirror_sync_*, future op_types)

Issue / PR / release events use gitea's pipe-separated
`<index>|<title>` content field; pushes have JSON-encoded content.

Host stamping: parse_gitea_event injects `_host` into each row's
payload so the reshape layer can construct web URLs without a
config dependency. Multi-host gitea would still work as long as
each source instance has its own host configured.

Worker config:
  GITEA_HOST                  default git.lair.cafe
  GITEA_USER                  default grenade
  GITEA_TOKEN                 optional (raises rate limit; required
                                for private repo activity to surface)
  GITEA_POLL_INTERVAL_SECS    default 600

Tests: +2 in moments-data (commit_repo parses, private flag
captured), +4 in moments-core (commit_repo with body, create_issue
pipe-content, merge icon swap, fallback) — 27 total green.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

crates/moments-data/src/lib.rs

@@ -1,3 +1,4 @@
+pub mod gitea;
 pub mod github;
 pub mod github_search;