feat: add per-file +/− summary and noise-filtered scope to review prompts

Emit a ### Changed Files Markdown table (| File | +/− | Type | rows plus
total added/removed) ahead of the raw diff in both committed and
uncommitted review prompts, parsed from the diff via the shared
parseDiff engine. Add an ### Excluded Files (n) section listing filtered
noise (path, +/− counts, reason), and replace byte-truncation of oversized
diffs with a file-list + read instruction when the cleaned diff exceeds
50KB or touches more than 20 files.

Also: distinguish diff-computation failure from genuinely no changes in the
review loop (tri-state result, never treats a broken base ref as a clean
verified task), map critical→blocker in finding severity parsing, inject a
per-review custom focus/instructions section from config, and make the
noise-filter ignore rules project-configurable via review.extraIgnorePatterns
and review.ignorePaths. Add same-model retry before cycling to the next
model in task/follow-up/fix sessions.

AGENTS.md

@@ -126,9 +126,20 @@ Key config fields in `execution`:
   loop startup via `selectLoopOptions`; review is asked FIRST, commit is
   mandated when review is on)
 - `models` — slot-aware round-robin model list for parallel mode, with
-  automatic failover to the next model per task
+  failover to the next model per task (only after exhausting same-model
+  retries, see `maxSameModelAttempts`)
+- `maxSameModelAttempts` — max attempts on the SAME model before cycling to
+  the next model on failure (default 5, matching pi's normal retry count).
+  Applies to task execution, commit/review follow-up sessions, and
+  review-fix re-execution alike
 - `implModel` / `commitModel` / `reviewModel` — `<provider>/<model>` strings
   resolved via `resolveModelSpec` in `utils.ts`
+- `prompts.reviewFocus` — per-review custom focus/instructions, injected as a
+  `## Custom Review Focus` section in review prompts
+- `review.extraIgnorePatterns` — extra noise-filter exclusion regexes (file
+  paths) merged into the default rules
+- `review.ignorePaths` — pathspec allowlist keeping matching files in review
+  scope even when a default noise rule would exclude them
 - `maxReviewRetries` / `reviewBlockOnFail` — review-gated loop retry behavior
 - `worktrees` — `"never" | "parallel" | "always"` git worktree isolation
   (default `"parallel"`; see `shouldUseWorktrees` in `src/executor.ts`)