fix: address all Cubic P2 review issues

- session-utils: log SDK errors instead of silent swallow
- opencode-message-dir: fix indentation, improve error log format
- storage: use session.list for sessionExists (handles empty sessions)
- storage.test: use resetStorageClient for proper SDK client cleanup
- todo-sync: add content-based fallback for id-less todo removal

src/tools/session-manager/storage.test.ts

@@ -469,23 +469,18 @@ describe("session-manager storage - SDK path (beta mode)", () => {
   })
 
   test("SDK path returns empty array when client is not set", async () => {
-    // given - beta mode enabled but no client set
+    //#given beta mode enabled but no client set
     mock.module("../../shared/opencode-storage-detection", () => ({
       isSqliteBackend: () => true,
       resetSqliteBackendCache: () => {},
     }))
 
-    // Reset SDK client to ensure "client not set" case is exercised
-    const { setStorageClient } = await import("./storage")
-    setStorageClient(null as any)
-
-    // Re-import without setting client
-    const { readSessionMessages } = await import("./storage")
-
-    // when - calling readSessionMessages without client set
+    //#when client is explicitly cleared and messages are requested
+    const { resetStorageClient, readSessionMessages } = await import("./storage")
+    resetStorageClient()
     const messages = await readSessionMessages("ses_test")
 
-    // then - should return empty array since no client and no JSON fallback
+    //#then should return empty array since no client and no JSON fallback
     expect(messages).toEqual([])
   })
 })

src/tools/session-manager/storage.ts

@@ -141,9 +141,9 @@ export function getMessageDir(sessionID: string): string | null {
 export async function sessionExists(sessionID: string): Promise<boolean> {
   if (isSqliteBackend() && sdkClient) {
     try {
-      const response = await sdkClient.session.messages({ path: { id: sessionID } })
-      const messages = response.data as unknown[] | undefined
-      return Array.isArray(messages) && messages.length > 0
+      const response = await sdkClient.session.list()
+      const sessions = (response.data || []) as Array<{ id?: string }>
+      return sessions.some((s) => s.id === sessionID)
     } catch {
       return false
     }