fix(lody): fall back to local when Git state fails

[pythonlearner1025]

What and why

An invited member can arrive at the local-project composer with the global worktree preference already persisted and a box whose local-project/git-state request fails. Lody already computes effectiveWorkdirMode === 'local', renders the worktree toggle off, and builds a local ProjectRef; two later submit gates nevertheless inspect the selected worktree value and strand both click and Enter submission.

The original version of this PR moved BlitzOS's global seed behind an asynchronous box-local probe. Review found two problems with that approach:

• the preference is shared across workspaces on the origin, so a healthy box can seed it before the browser visits an unhealthy box;
• moving the seed after first render breaks the healthy-box worktree default because the composer does not react to the later global-localStorage write.

This revision fixes the failure at the actual boundary:

• restore the pre-render worktree seed and the existing repository-publication contract;
• keep Send blocked while a requested worktree's Git state is loading;
• after a terminal Git-state error, allow the component's existing effective local fallback through both the button and keyboard-submit paths;
• add a regression for the cross-workspace persisted-preference case;
• declare vendored seam patch 18 and include an upstream Lody PR sketch.

No runtime-boundary payload changes.

Vendor/upstream burden

Low. The behavioral change is three small hunks in two Lody component files, adds no API or Blitz-specific capability, and only reconciles submit gating with Lody's existing effective-mode fallback. vendor/lody/BLITZ-PATCHES.md includes the merge drill and plans/evidence/lody-git-state-fallback-pr.md is the upstream contribution sketch. Drop the seam when upstream adopts the rule.

Validation

• GitHub CI run 918 — pass
• npm run typecheck — pass
• npm run lint:gate — pass (66 anti-slop findings, baseline unchanged)
• npm test — pass in CI
• focused webapp regression set locally — 75 passed, 1 skipped
• local full run's one real-relay timeout passed 6/6 immediately in isolation

Checklist

• npm run typecheck passes
• npm run lint:gate passes
• npm test passes
• lint-baseline.json was not raised
• No new payload crosses a runtime boundary
• No Go changes
• Seam documentation and upstream PR sketch added