CI: assign-id workflow passes --dry-run-only, a flag the binary does not have

[explosivebit]

What is wrong

.github/workflows/assign-id.yml:73 sets

DRY_RUN_FLAG="--dry-run-only"

and expands it unquoted into the invocation at line 77-81:

./target/release/forgeplan ci-assign-id \
  --pr "$PR_NUMBER" --repo "${{ github.repository }}" \
  --base origin/dev --json $DRY_RUN_FLAG > /tmp/assignment.json

forgeplan ci-assign-id has no --dry-run-only flag. Its real flag set is:

--auto-suffix --base --dry-run --head --json --pr --repo --workspace

So the manual dry-run-only input (workflow_dispatch) is the one path that breaks: instead of
a dry run, the step dies on error: unexpected argument '--dry-run-only' found, with
tip: a similar argument exists: '--dry-run'.

Evidence

• clap declaration: crates/forgeplan-cli/src/main.rs:802 (dry_run: bool, long only)
• grep -rn 'dry-run-only' crates/forgeplan-cli/ → no hits
• forgeplan ci-assign-id --help on 0.37.0 lists --dry-run, never --dry-run-only
• the workflow's own docs page already documents the rejection:
  website/src/content/docs/docs/cli/ci-assign-id.md (the --dry-run-only error transcript)

Fix

Line 73 → DRY_RUN_FLAG="--dry-run". Worth a smoke test of the workflow_dispatch path, since
only that input reaches the broken branch.

Revisit trigger

Reopen/act if a manual dry-run-only dispatch is ever run before this lands - nobody has, which
is why the branch survived.