Fix: untrack accidentally-committed worktree submodule + gitignore .claude/

The previous commit (beb123a) used `git add -A` to stage the rename
of scripts/ → tests/quality/. That swept in `.claude/worktrees/
trusting-jones-afaa7e` as a submodule reference (mode 160000)
because the worktree directory has its own `.git` file and `.claude/`
turned out to NOT actually be in the gitignore — earlier searches
that suggested it was matched a tab-prefixed pattern that git was
reading literally.

This commit:
- `git rm --cached` on the spurious submodule entry, removing it
  from the index without touching the worktree on disk.
- Adds a real `.claude/` rule to `.gitignore` so future `git add -A`
  invocations skip it.

The worktree directory itself stays where it is; only the bogus
submodule pointer in main's tree is removed.

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

Author: LEANDERANTONY

.claude/worktrees/trusting-jones-afaa7e

@@ -277,4 +277,6 @@ reports/
 *.tsbuildinfo
 
 # Local design/planning notes
-VISUAL_LOOP_MVP.md
+VISUAL_LOOP_MVP.md
+# Claude Code session state + worktrees (harness-managed, not source)
+.claude/