Merge remote-tracking branch 'origin/master' into worktree/pr504-retarget-latest-master

# Conflicts:
#	docs/event-producer-consumer.md
#	examples/tui-agent/README.md
#	examples/tui-agent/composition.md
#	examples/tui-agent/cordis.yml
#	examples/tui-agent/tests/snapshots/multi-turn-conversation/terminal.expected.txt
#	examples/tui-agent/tests/tui-keyless-smoke.e2e.ts
#	packages/ui/tui/README.md
#	vitest.config.ts

vitest.config.ts

@@ -22,6 +22,23 @@ const windowsCoverageExclusions = process.platform === 'win32'
     ]
   : []
 
+const testIncludes = [
+  'packages/*/*/tests/**/*.spec.{ts,tsx}',
+  'examples/*/tests/**/*.spec.ts',
+  'scripts/**/*.spec.ts',
+]
+
+// These suites exercise process-global state, process APIs, or timing-sensitive process I/O
+// that worker threads cannot isolate reliably under aggregate gate contention.
+// Keep the narrow exception in forks while the rest of the inventory avoids per-file processes.
+const processBoundTests = [
+  'packages/bash/bash-local/tests/run.spec.ts',
+  'packages/context/time-context/tests/time-context.spec.ts',
+  'packages/llm/llm-pi-ai/tests/adapter.spec.ts',
+  'packages/ui/app-boot/tests/app-boot.spec.ts',
+  'packages/workflow/workflow-workerthread/tests/session.spec.ts',
+]
+
 export default defineConfig({
   // Native path resolution reads each package's nearest tsconfig, but only the root defines
   // workspace paths. Keep this plugin pinned to the root map so bare package imports resolve
@@ -32,8 +49,35 @@ export default defineConfig({
   test: {
     setupFiles: ['./scripts/test-invariants.ts'],
     // .tsx: client component specs (jsdom via per-file @vitest-environment pragma).
-    include: ['packages/*/*/tests/**/*.spec.{ts,tsx}', 'examples/*/tests/**/*.spec.ts', 'scripts/**/*.spec.ts'],
+    include: testIncludes,
     exclude: windowsUnsupportedPackages.map(path => `${path}/tests/**/*.spec.ts`),
+    // One coverage invocation aggregates both projects. Most suites use threads
+    // for lower startup/IPC overhead; only explicit process-bound suites fork.
+    projects: [
+      {
+        plugins: [tsconfigPaths({ projects: ['./tsconfig.vitest.json'] })],
+        test: {
+          name: 'thread-safe',
+          pool: 'threads',
+          setupFiles: ['./scripts/test-invariants.ts'],
+          include: testIncludes,
+          exclude: [
+            ...windowsUnsupportedPackages.map(path => `${path}/tests/**/*.spec.ts`),
+            ...processBoundTests,
+          ],
+        },
+      },
+      {
+        plugins: [tsconfigPaths({ projects: ['./tsconfig.vitest.json'] })],
+        test: {
+          name: 'process-bound',
+          pool: 'forks',
+          setupFiles: ['./scripts/test-invariants.ts'],
+          include: processBoundTests,
+          exclude: windowsUnsupportedPackages.map(path => `${path}/tests/**/*.spec.ts`),
+        },
+      },
+    ],
     coverage: {
       provider: 'v8',
       // Coverage measures OUR runtime source. Types-only files carry no