82e4a564aa
Tool-surface audit pass: - FILE OPERATIONS rewritten so each line states the niche, not just the verb. read_file mentions PDF auto-extraction + `pages` slicing. - New SEARCH section consolidates grep_files / file_search / web_search / fetch_url so the model sees them next to each other and picks the right one. fetch_url (#33) added; previously absent from the prompt. - request_user_input pulled out of FILE OPERATIONS into its own USER section — it never belonged there. - SUB-AGENTS list shrinks by 3: drops `spawn_agent` (use `agent_spawn`), `close_agent` (use `agent_cancel`), and the `agent_assign / assign_agent` dual-name. The underlying dispatchers still resolve those names, so existing sessions don't break — they just no longer pollute the model's tool list. Adds `docs/TOOL_SURFACE.md` with the rationale, the v0.5.1 final surface, and the dropped aliases. Calls out that grep_files is pure-Rust (no rg/grep shell-out, so the "fall back to grep" AC from #35 is vacuously satisfied — the tool has no shell dependency to fall back from). Closes #35.