VS Code sidebar 'Search sessions…' is title-only — add full-text search over session content

Preflight Checklist

• [x] I have searched existing requests and this feature hasn't been requested yet
• [x] This is a single feature request (not multiple features)

Problem Statement

The VS Code extension's sidebar has a "Search sessions…" input that only filters on the visible session label (title / truncated last-prompt). It does not search inside session transcripts (.jsonl files).

Effect: users cannot find a past session by typing a distinctive phrase, file name, identifier, symbol, or error message that appeared inside the conversation — only what happens to be in the sidebar label.

This compounds with #50340 (sidebar labels often don't reflect aiTitle). A conversation could be entirely about a specific file or feature, yet if none of those strings appear in the label, the sidebar search can't find it. The session effectively becomes unfindable once it scrolls off the top of the list, unless the user manually greps .jsonl files on disk.

Related: #30599 is open for full-text search in CLI claude --resume and TUI /resume. This issue covers the VS Code sidebar specifically (area:ide, platform:vscode).

Proposed Solution

Extend the sidebar "Search sessions…" input to match not just the session label, but also content inside the session transcript — at minimum user messages, ideally all message text.

Options from lightest to heaviest:

1. Match against user messages only (usually enough — users recall what they asked).
2. Match against all message text (user + assistant) with snippet preview on hover / on match.
3. Full indexed FTS (e.g. SQLite FTS5) over .jsonl files for large session histories.

A Claude.ai-style search UI — matches highlighted, snippet preview, click to resume — would be a big usability win.

Alternative Solutions

• Manual grep on %USERPROFILE%\\.claude\\projects\\<slug>\\*.jsonl. Works but is outside the IDE, doesn't integrate with "resume session" action.
• The workaround shell script from #30599 (claude-search). Same limitation — terminal-only, not integrated with the sidebar.
• Remembering the approximate date and scrolling the sidebar. Breaks down once there are hundreds of sessions.

Priority

Critical - Blocking my work

Feature Category

CLI commands and flags

Use Case Example

Example scenario:

1. Two days ago I worked on a session about a specific module (e.g. a file name like XXXX_WIDGET.fmb).
2. Today I want to resume that conversation.
3. I type the file name / module name into "Search sessions…".
4. Expected: the matching session appears.
5. Actual: no match, because the session label says something like "Just put the corrected file into the c:\\Tem..." (a later user message) — the file name is only inside the transcript.

This happens every time the aiTitle or user-visible label doesn't explicitly contain the thing you remember. Which is most of the time.

Additional Context

Environment:

• Claude Code: 2.1.89
• VS Code: 1.116.0
• OS: Windows 11 Pro 10.0.26200

Related issues:

• #30599 — open; full-text search for CLI --resume / TUI /resume. Same concept, different surface.
• #50340 — open; sidebar label often doesn't reflect aiTitle, which makes title-only search even less useful.
• #8701, #6455 — prior requests (closed/locked).

Suggested labels: area:ide, enhancement, platform:vscode.