fix(pr): route create pr through ship workflow

[astyfx]

Summary

Create PR now dispatches the active task through the shared ship skill, eliminating the renderer-owned PR draft orchestration and its cross-workspace timing races.

Changes

Fixes

• pr: scope Create PR and Continue operation state to the active workspace
• pr: require the active workspace skill catalog before dispatching ship
• pr: remove the stale PR draft dialog and draft action
• docs: document the ship workflow and updated PR contract

Test Evidence

• bun run typecheck
• bun run build
• Focused skill, workspace-integrity, project, command-palette, theme, and settings tests passed
• The isolated existing steering regression in tests/bridge-persistence-regression.test.ts still expects the pre-existing call shape and fails on the unrelated enabled: false field

Notes

The repository allows squash merges only. The ship workflow is expected to create a ready PR and queue auto-merge after this PR is merged.