refactor: wave 1 - extract leaf modules, rename catch-all files, split index.ts hooks

- Split 25+ index.ts files into hook.ts + extracted modules
- Rename all catch-all utils.ts/helpers.ts to domain-specific names
- Split src/tools/lsp/ into ~15 focused modules
- Split src/tools/delegate-task/ into ~18 focused modules
- Separate shared types from implementation
- 155 files changed, 60+ new files created
- All typecheck clean, 61 tests pass

src/hooks/directory-agents-injector/finder.ts

@@ -0,0 +1,38 @@
+import { existsSync } from "node:fs";
+import { dirname, join, resolve } from "node:path";
+
+import { AGENTS_FILENAME } from "./constants";
+
+export function resolveFilePath(rootDirectory: string, path: string): string | null {
+  if (!path) return null;
+  if (path.startsWith("/")) return path;
+  return resolve(rootDirectory, path);
+}
+
+export function findAgentsMdUp(input: {
+  startDir: string;
+  rootDir: string;
+}): string[] {
+  const found: string[] = [];
+  let current = input.startDir;
+
+  while (true) {
+    // Skip root AGENTS.md - OpenCode's system.ts already loads it via custom()
+    // See: https://github.com/code-yeongyu/oh-my-opencode/issues/379
+    const isRootDir = current === input.rootDir;
+    if (!isRootDir) {
+      const agentsPath = join(current, AGENTS_FILENAME);
+      if (existsSync(agentsPath)) {
+        found.push(agentsPath);
+      }
+    }
+
+    if (isRootDir) break;
+    const parent = dirname(current);
+    if (parent === current) break;
+    if (!parent.startsWith(input.rootDir)) break;
+    current = parent;
+  }
+
+  return found.reverse();
+}