fix(task): filter lock files from commit message diff input

packages/coding-agent/CHANGELOG.md

@@ -10,7 +10,7 @@
 
 - Added `fuse-overlay` isolation mode for subagents using `fuse-overlayfs` (copy-on-write overlay, no baseline patch apply needed)
 - Added `task.isolation.merge` setting (`patch` or `branch`) to control how isolated task changes are integrated back. `branch` mode commits each task to a temp branch and cherry-picks for clean commit history
-- Added `task.isolation.commits` setting (`generic` or `ai`) for nested repo commit messages. `ai` mode uses a smol model to generate conventional commit messages from diffs
+- Added `task.isolation.commits` setting (`generic` or `ai`) for commit messages on isolated task branches and nested repos. `ai` mode uses a smol model to generate conventional commit messages from diffs
 - Nested non-submodule git repos are now discovered and handled during task isolation (changes captured and applied independently from parent repo)
 - Added `task.eager` setting to encourage the agent to delegate work to subagents by default
 
@@ -20,6 +20,9 @@
 - Fixed nested repo patches conflicting when multiple tasks contribute to the same repo (baseline untracked files no longer leak into patches)
 - Nested repo changes are now committed after patch application (previously left as untracked files)
 - Failed tasks no longer create stale branches or capture garbage patches (gated on exit code)
+- Merge failures (e.g. conflicting patches) are now non-fatal — agent output is preserved with `merge failed` status instead of `failed`
+- Stale branches are cleaned up when `commitToBranch` fails
+- Commit message generator filters lock files from diffs before AI summarization
 
 ## [13.2.0] - 2026-02-23
 ### Breaking Changes

packages/coding-agent/DEVELOPMENT.md

@@ -907,11 +907,13 @@ Despite the name `runSubprocess`, `packages/coding-agent/src/task/executor.ts` c
 What _is_ isolated is execution context and artifacts, not process memory:
 
 - Optional filesystem isolation is controlled by the `task.isolation.mode` setting (`"none"`, `"worktree"`, or `"fuse-overlay"`).
-  - **worktree**: `ensureWorktree(...)`, `applyBaseline(...)`, `captureDeltaPatch(...)`, `cleanupWorktree(...)`.
-  - **fuse-overlay**: `ensureFuseOverlay(...)` (mounts a copy-on-write overlay via `fuse-overlayfs`), `captureDeltaPatch(...)`, `cleanupFuseOverlay(...)`. No baseline apply step needed since the overlay reflects the full working tree.
+  - **worktree**: `ensureWorktree(...)`, `applyBaseline(...)`, `captureDeltaPatch(...)`, `cleanupWorktree(...)`. Nested non-submodule git repos are discovered and handled independently.
+  - **fuse-overlay**: `ensureFuseOverlay(...)` (mounts a copy-on-write overlay via `fuse-overlayfs`), `captureDeltaPatch(...)`, `cleanupFuseOverlay(...)`. No baseline apply needed since the overlay reflects the full working tree. Fails outright if mount fails.
 - The `task.isolation.merge` setting controls how isolated changes are integrated back:
   - **patch** (default): captures a diff via `captureDeltaPatch(...)`, combines patches, and applies with `git apply`.
-  - **branch**: each task commits to a temp branch (`omp/task/<id>`) via `commitToBranch(...)`, then `mergeTaskBranches(...)` merges them sequentially with `--no-ff` merge commits.
+  - **branch**: each task commits to a temp branch (`omp/task/<id>`) via `commitToBranch(...)`, then `mergeTaskBranches(...)` cherry-picks them sequentially onto HEAD. If `git apply` fails inside `commitToBranch`, the error is non-fatal — the agent result is preserved with a `merge failed` status.
+- The `task.isolation.commits` setting (`generic` or `ai`) controls commit messages for branch commits and nested repo patches. `ai` mode uses a smol model to generate conventional commit messages from diffs.
+- Nested repo patches are applied via `applyNestedPatches(...)` after the parent merge, grouped by repo with one commit per repo.
 - Child session JSONL/markdown outputs are written under the task artifacts directory (`<id>.jsonl`, `<id>.md`, and in isolated mode `<id>.patch`).
 
 ### Tooling Surface in Child Sessions

packages/coding-agent/src/task/index.ts

@@ -806,7 +806,6 @@ export class TaskTool implements AgentTool<TaskSchema, TaskToolDetails, Theme> {
 
 					if (isolationMode === "fuse-overlay") {
 						isolationDir = await ensureFuseOverlay(repoRoot, task.id);
-						// Overlay already reflects the full working tree state — no baseline apply needed
 					} else {
 						isolationDir = await ensureWorktree(repoRoot, task.id);
 						await applyBaseline(isolationDir, baseline);

packages/coding-agent/src/utils/commit-message-generator.ts

@@ -14,19 +14,18 @@ import commitSystemPrompt from "../prompts/system/commit-message-system.md" with
 const COMMIT_SYSTEM_PROMPT = renderPromptTemplate(commitSystemPrompt);
 const MAX_DIFF_CHARS = 4000;
 
-/** Paths that should be excluded from commit message generation diffs. */
-const NOISE_PATH_PREFIXES = ["node_modules/", ".yarn/", ".pnp.", "dist/", "build/", ".next/", "coverage/"];
+/** File patterns that should be excluded from commit message generation diffs. */
+const NOISE_SUFFIXES = [".lock", ".lockb", "-lock.json", "-lock.yaml"];
 
-/** Strip diff hunks for noisy paths that drown out real changes. */
+/** Strip diff hunks for noisy files that drown out real changes. */
 function filterDiffNoise(diff: string): string {
 	const lines = diff.split("\n");
 	const filtered: string[] = [];
 	let skip = false;
 	for (const line of lines) {
 		if (line.startsWith("diff --git ")) {
-			// Extract b/ path from "diff --git a/... b/..."
 			const bPath = line.split(" b/")[1];
-			skip = bPath != null && NOISE_PATH_PREFIXES.some(p => bPath.startsWith(p));
+			skip = bPath != null && NOISE_SUFFIXES.some(s => bPath.endsWith(s));
 		}
 		if (!skip) filtered.push(line);
 	}