refactor: wave 2 - split atlas, auto-update-checker, session-recovery, todo-enforcer, background-task hooks

- Extract atlas/ into 15 focused modules (hook, event handler, tool policies, types, etc.)
- Split auto-update-checker into checker/ and hook/ subdirectories with single-purpose files
- Decompose session-recovery into separate recovery strategy files per error type
- Extract todo-continuation-enforcer from monolith to directory with dedicated modules
- Split background-task/tools.ts into individual tool creator files
- Extract command-executor, tmux-utils into focused sub-modules
- Split config/schema.ts into domain-specific schema files
- Decompose cli/config-manager.ts into focused modules
- Rollback skill-mcp-manager, model-availability, index.ts splits that broke tests
- Fix all import path depths for moved files (../../ -> ../../../)
- Add explicit type annotations to resolve TS7006 implicit any errors

Typecheck: 0 errors
Tests: 2359 pass, 5 fail (all pre-existing)

src/hooks/auto-update-checker/checker/plugin-entry.ts

@@ -0,0 +1,38 @@
+import * as fs from "node:fs"
+import type { OpencodeConfig } from "../types"
+import { PACKAGE_NAME } from "../constants"
+import { getConfigPaths } from "./config-paths"
+import { stripJsonComments } from "./jsonc-strip"
+
+export interface PluginEntryInfo {
+  entry: string
+  isPinned: boolean
+  pinnedVersion: string | null
+  configPath: string
+}
+
+export function findPluginEntry(directory: string): PluginEntryInfo | null {
+  for (const configPath of getConfigPaths(directory)) {
+    try {
+      if (!fs.existsSync(configPath)) continue
+      const content = fs.readFileSync(configPath, "utf-8")
+      const config = JSON.parse(stripJsonComments(content)) as OpencodeConfig
+      const plugins = config.plugin ?? []
+
+      for (const entry of plugins) {
+        if (entry === PACKAGE_NAME) {
+          return { entry, isPinned: false, pinnedVersion: null, configPath }
+        }
+        if (entry.startsWith(`${PACKAGE_NAME}@`)) {
+          const pinnedVersion = entry.slice(PACKAGE_NAME.length + 1)
+          const isPinned = pinnedVersion !== "latest"
+          return { entry, isPinned, pinnedVersion: isPinned ? pinnedVersion : null, configPath }
+        }
+      }
+    } catch {
+      continue
+    }
+  }
+
+  return null
+}