fix: keep valid older agent packages usable after desktop updates

Accept package-declared OpenCode, Node and koffi versions instead of desktop release pins. Preserve signature, hash, protocol and package-internal version consistency checks.

Validate both cached 0.11.18 packages and Linux x64 installation, bootstrap, health and stop. Related regression suite: 326 passed, 1 skipped; unrelated full-workspace check failures are recorded in the remote Host design.

Release note: Desktop updates no longer reject intact older Agent packages solely because their bundled runtime versions differ.

src/agent-daemon/runtime-bundle-test-fixture.ts

@@ -66,6 +66,7 @@ export const TEST_REMOTE_RUNTIME_LOCK: RemoteRuntimeLock = {
 
 export async function createRuntimeBundleTestFixture(
   overrides: {
+    runtimeVersion?: RemoteRuntimeBundleManifest['runtimeVersion']
     sourcePackage?: RemoteRuntimeBundleManifest['sourcePackage']
     directoryDigest?: string
   } = {}
@@ -87,7 +88,7 @@ export async function createRuntimeBundleTestFixture(
     formatVersion: 2,
     product: 'GoodBuddy',
     runtimeId: 'opencode',
-    runtimeVersion: '1.18.29',
+    runtimeVersion: overrides.runtimeVersion ?? '1.18.29',
     provider: 'opencode',
     platform: 'linux',
     architecture: 'x64',
@@ -127,7 +128,7 @@ export async function createRuntimeBundleTestFixture(
     licenses: [
       {
         package: 'opencode-ai',
-        version: '1.18.29',
+        version: overrides.runtimeVersion ?? '1.18.29',
         spdx: 'MIT',
         path: 'licenses/opencode.txt'
       }