feat: add Google code retrieval across desktop CLI and MCP

apps/desktop/tests/match-display.test.mjs

@@ -80,3 +80,8 @@ test('optional reasons use real source routes and never claim semantic word conf
   assert.equal(matchExplanation({match_kind:'hybrid',source:{kind:'page',number:2}}).semanticPassage,false);
   assert.doesNotMatch(JSON.stringify(text),/confidence|percent|importance/);
 });
+
+test('code passage reasons retain actual indexed source line', () => {
+  assert.match(matchExplanation({match_kind:'semantic', source:{kind:'line',number:97}}).reason, /at line 97/);
+  assert.match(matchExplanation({match_kind:'hybrid', source:{kind:'line',number:97}}).reason, /showing the passage at line 97/);
+});

apps/desktop/tests/search-state.test.mjs

@@ -1,6 +1,6 @@
 import test from 'node:test';
 import assert from 'node:assert/strict';
-import { LatestLane, AutomaticIndexGate, emptySearchState, semanticAvailable, SEMANTIC_SETTLE_MS } from '../src/search-state.ts';
+import { LatestLane, AutomaticIndexGate, emptySearchState, semanticAvailable, SEMANTIC_SETTLE_MS, scopedFilters } from '../src/search-state.ts';
 const settle = () => new Promise(resolve => setImmediate(resolve));
 
 test('coalesces queued keystrokes and discards stale responses', async () => {
@@ -78,3 +78,32 @@ test('old committed semantic generation stays available during rebuild, activati
   assert.equal(semanticAvailable({ready: true, generation: 2, embedding: false}), true);
   assert.equal(SEMANTIC_SETTLE_MS, 120);
 });
+
+test('scope snapshots freeze all filters independently of later control changes', () => {
+  const controls = { extension: 'rs', folder: '/project' };
+  const all = scopedFilters('all', controls);
+  const code = scopedFilters('code', controls);
+  controls.extension = 'pdf';
+  assert.equal(all.code_only, false);
+  assert.equal(code.code_only, true);
+  assert.equal(code.extension, 'rs');
+  assert.equal(code.folder, '/project');
+  assert.throws(() => { code.code_only = false; }, TypeError);
+  assert.throws(() => scopedFilters('unknown', {}), /scope/);
+});
+test('same-query scope change discards old lane output and runs latest scoped request', async () => {
+  let revision = 1; let release; const seen = []; const accepted = [];
+  const lane = new LatestLane(async request => {
+    seen.push(request.filters.code_only);
+    if (request.id === 1) await new Promise(resolve => { release = resolve; });
+    if (request.id === revision) accepted.push(request);
+  }, request => request.id === revision, () => assert.fail('Unexpected failure'));
+  lane.submit({id: 1, query: 'parse configuration', filters: scopedFilters('all', {})});
+  revision = 2;
+  lane.submit({id: 2, query: 'parse configuration', filters: scopedFilters('code', {extension: 'rs'})});
+  release(); await settle();
+  assert.deepEqual(seen, [false, true]);
+  assert.equal(accepted.length, 1);
+  assert.equal(accepted[0].filters.code_only, true);
+  assert.equal(accepted[0].filters.extension, 'rs');
+});