feat(launch): force-load fleet-critical Pi skills + reconcile skill docs

Pi workers launched via `mosaic [yolo] pi` never loaded any skill because
buildPiSkillArgs emitted `--no-skills` whenever MOSAIC_PI_SKILL_MODE was
unset (the default everywhere), so maintained `~/.config/mosaic/tools/`
wrappers stayed invisible and workers improvised raw `tmux send-keys` /
`tea` / `gh`. An explicit `--skill` overrides `--no-skills` for that path,
so we now force-load a small fleet-critical set (default: `mosaic-tools`)
on every Pi launch regardless of mode — no full-catalog context bloat.

- launch.ts: add DEFAULT_PI_FORCE_SKILLS + forcedPiSkillArgs(); merge into
  every buildPiSkillArgs() return path (existsSync-guarded → no-op until the
  skill is synced). Override via MOSAIC_PI_FORCE_SKILLS (colon-separated;
  empty string disables).
- launch.spec.ts: deterministic 4th-param injection + force-load coverage.
- runtime/pi/RUNTIME.md: reconcile the "skills load natively" drift with the
  real default-off + force-load + MOSAIC_PI_SKILL_MODE behavior.
- templates/agent/**: fix stale `~/.config/mosaic/rails/` → `tools/` (60
  occurrences across 12 scaffold templates; `rails/` no longer exists).

Companion skill `mosaic-tools` ships in mosaic/agent-skills.
Follow-up (NOT auto-applied): live fleet needs `mosaic-sync-skills` +
launcher upgrade to pick up the new skill on running sessions.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01QoYiBeKNh3BiYtAJS5Z587

packages/mosaic/framework/templates/agent/CLAUDE.md.template

@@ -135,7 +135,7 @@ ${QUALITY_GATES}
 ## Issue Tracking
 
 Use external git provider issues when available. If no external provider exists, `docs/TASKS.md` is the canonical tracker for tasks, milestones, and issue-equivalent work.
-For issue/PR/milestone operations, detect platform and use `~/.config/mosaic/rails/git/*.sh` wrappers first; do not use raw `gh`/`tea`/`glab` as first choice.
+For issue/PR/milestone operations, detect platform and use `~/.config/mosaic/tools/git/*.sh` wrappers first; do not use raw `gh`/`tea`/`glab` as first choice.
 If wrapper-driven merge/CI/issue-closure fails, report blocker with exact failed wrapper command and stop.
 Do NOT stop at "PR created" and do NOT ask "should I merge?" or "should I close the issue?" for routine delivery flow.
 
@@ -147,9 +147,9 @@ Do NOT stop at "PR created" and do NOT ask "should I merge?" or "should I close
 5. Ensure `docs/PRD.md` or `docs/PRD.json` exists and is current before coding.
 6. Create scratchpad: `docs/scratchpads/{task-id}-{short-name}.md` and include issue/internal ref.
 7. Update `docs/TASKS.md` status + issue/internal ref before coding.
-8. Before push, run CI queue guard: `~/.config/mosaic/rails/git/ci-queue-wait.sh --purpose push -B main`.
+8. Before push, run CI queue guard: `~/.config/mosaic/tools/git/ci-queue-wait.sh --purpose push -B main`.
 9. Open PR to `main` for delivery changes (no direct push to `main`).
-10. Before merge, run CI queue guard: `~/.config/mosaic/rails/git/ci-queue-wait.sh --purpose merge -B main`.
+10. Before merge, run CI queue guard: `~/.config/mosaic/tools/git/ci-queue-wait.sh --purpose merge -B main`.
 11. Merge PRs that pass required checks and review gates with squash strategy only.
 12. Reference issues/internal refs in commits (`Fixes #123`, `Refs #123`, or `Refs TASKS:T1`).
 13. Close issue/internal task only after testing and documentation gates pass, PR merge is complete, and CI/pipeline status is terminal green.
@@ -176,10 +176,10 @@ Run independent reviews:
 
 ```bash
 # Code quality review (Codex)
-~/.config/mosaic/rails/codex/codex-code-review.sh --uncommitted
+~/.config/mosaic/tools/codex/codex-code-review.sh --uncommitted
 
 # Security review (Codex)
-~/.config/mosaic/rails/codex/codex-security-review.sh --uncommitted
+~/.config/mosaic/tools/codex/codex-security-review.sh --uncommitted
 ```
 
 **Fallback:** If Codex is unavailable, use Claude's built-in review skills.