fix(coding-agent): corrected issue-pr diff URL parsing to list outputs

- Fixed `issue://owner/diff` and `pr://owner/diff` parsing so they resolve to issue and PR list outputs.
- Fixed `pr` short-form parsing by requiring `scheme==='pr'` and a numeric host before `diff` matching.
- Fixed PR unified-diff parsing to decode quoted header paths and count `----`/`++++` hunk lines as one deletion/addition.
- Fixed `read` error rendering to emit status blocks with cleaned, range-aware, tab-normalized lines.
- Stopped `github-cache` from chmod-ing existing parent directories, preserving pre-existing permission modes.

packages/coding-agent/src/tools/github-cache.ts

@@ -64,7 +64,6 @@ function ensureParentDir(filePath: string): void {
 	try {
 		const dir = path.dirname(filePath);
 		fs.mkdirSync(dir, { recursive: true, mode: 0o700 });
-		fs.chmodSync(dir, 0o700);
 	} catch (err) {
 		logger.debug("github cache: failed to create private parent dir", { err: String(err) });
 	}