[FEATURE REQUEST] Grep/Fuzzy Find Over Session Content for Better Session Discovery

What I'd like

A way to search through previous session content using grep or a fuzzy finder interface, making it easy to find and resume old sessions based on what I was working on.

Why

Currently, finding a specific previous session requires remembering its exact ID or browsing through a chronological list. When you have many sessions, it's hard to locate "that session where I was working on the authentication bug" or "the one where I discussed the React refactor."

Example

Running something like claude --grep "authentication bug" or pressing Ctrl+F to invoke a fuzzy finder that searches across session messages and lets me interactively filter/select from matching sessions to resume.

Related

This relates to #2562 (session deletion and management tools), but focuses specifically on search and discovery capabilities rather than just tree management. Being able to search session content would dramatically improve the ability to navigate back to previous work.