feat(FN-1449): complete agent UI field parity with Agent Companies

This change aligns agent editing surfaces across dashboard UI, API payloads,
and import/template flows so every first-class editable agent field is
round-trippable.

Backend changes:
- Add memory and bundleConfig fields to POST/PATCH /api/agents routes
- Fix agent-companies-parser to use first-class fields (title, icon, role,
  reportsTo, instructionsText) instead of metadata fallbacks
- Update import dry-run preview to show more manifest fields

UI changes:
- Enable identity field editing (name, title, icon, role, reportsTo) in
  AgentDetailView ConfigTab
- Add instruction bundle configuration (mode, entry file, files, external
  path) to ConfigTab
- Add memory field to NewAgentDialog
- Fix AI generation mapping to preserve systemPrompt as instructionsText
- Update AgentImportModal preview to show icon, reportsTo, and instructions

Test fixes:
- Update parser tests for new first-class field behavior
- Add MissionExecutionLoop mock for serve tests

Documentation:
- Add agent field parity matrix to docs/agents.md
- Create changeset for @gsxdsm/fusion

packages/cli/src/commands/__tests__/serve.test.ts

@@ -344,6 +344,12 @@ vi.mock("@fusion/engine", () => ({
   StuckTaskDetector: mocks.stuckDetectorCtor,
   SelfHealingManager: mocks.selfHealingCtor,
   MissionAutopilot: mocks.missionAutopilotCtor,
+  MissionExecutionLoop: vi.fn().mockImplementation(() => ({
+    start: vi.fn(),
+    stop: vi.fn(),
+    tick: vi.fn().mockResolvedValue(undefined),
+    recoverActiveMissions: vi.fn().mockResolvedValue(undefined),
+  })),
   createAiPromptExecutor: vi.fn().mockResolvedValue(vi.fn().mockResolvedValue("ok")),
   HeartbeatMonitor: vi.fn().mockImplementation(() => ({
     start: vi.fn(),