fix(web): changed-files filter in the diff view now filters and fuzzy-matches

[MTVaught]

The "Filter changed files" input in the diff view's file picker never removed anything from the list. The filtered entries were only passed to the combobox's filteredItems prop, which Base UI uses solely to decide when to show the empty state; the explicit child items always rendered. The filter itself was also a plain substring match.

The list now renders the filtered entries, and filterDiffFiles ranks results with the shared searchRanking helper: substring hits on the path come first, ordered by where they appear, followed by subsequence (fuzzy) matches such as dfpnl for DiffPanel.tsx. Tests cover fuzzy matching, ranking, and the no-match case.

Verified with vp test run apps/web/src/lib/diffFileNavigation.test.ts, lint, and a web typecheck.

Work done by Claude Fable 5.1 via Claude Code in T3 Code.

[github-actions]

Thread transfer impact

✅ Thread transfer remains within every enforced ceiling.

Provider	Metric	Main baseline	This PR	Impact	PR ceiling
Codex	Total thread wire	13.6 KiB	13.6 KiB	0 B (0.0%)	15.1 KiB	✅
Codex	Thread snapshot wire	7.1 KiB	7.1 KiB	−2 B (−0.0%)	7.3 KiB	✅
Codex	Live turn WebSocket wire	6.6 KiB	6.6 KiB	+2 B (+0.0%)	7.8 KiB	✅
Codex	Live turn WebSocket decoded	57.1 KiB	57.1 KiB	0 B (0.0%)	66.4 KiB	✅
Codex	Live turn messages	10	10	0 (0.0%)	21	✅
Claude	Total thread wire	13.6 KiB	13.6 KiB	−13 B (−0.1%)	15.1 KiB	✅
Claude	Thread snapshot wire	7.1 KiB	7.1 KiB	+10 B (+0.1%)	7.3 KiB	✅
Claude	Live turn WebSocket wire	6.5 KiB	6.5 KiB	−23 B (−0.3%)	7.8 KiB	✅
Claude	Live turn WebSocket decoded	57.8 KiB	57.8 KiB	−44 B (−0.1%)	66.4 KiB	✅
Claude	Live turn messages	9	8	−1 (−11.1%)	21	✅

Baseline: 11c84de · PR result: 07ce6fb · Source CI: success

Scenario and decoded snapshot size

10 historical turns, 5 command tools per turn, 878.9 KiB retained MCP result per historical turn, and a 1.05 MiB retained result in the measured turn.

• Codex decoded thread snapshot: 114.0 KiB
• Claude decoded thread snapshot: 114.7 KiB

Updated in place by a trusted workflow. PR artifacts are strictly validated and never executed.