tui(M4.1): typed tool card renderers + diff hunks

[emal-avala]

Parent #390 (M4) · Epic #385

Classify tools into Bash/Read/Edit/Search/Fetch/Task/Mcp/Other; render running vs collapsed cards; Edit multi-hunk diff display via similar.

Acceptance

Snapshots per kind; failed auto-expand.

[emal-avala]

Triage against main @ 6eb1282 — mostly done, keep open for two gaps. Done: 8-kind classification (toolcard.rs:10-70, test :129); multi-hunk word-level diffs via similar (diffview.rs, landed recently). Remaining: (1) failed cards only widen to 5 result lines (layout.rs:393-400) — nothing inserts them into App.expanded, so 'failed auto-expand' is half-met; (2) rendering is one parameterized render_tool_card branching on kind only for the Edit diff path — fine architecturally, but there's no per-kind snapshot suite (single test layout.rs:622). Scope left ≈ auto-expand on error + snapshot tests.