feat(FN-2924): merge fusion/fn-2924

- Add task provenance display to TaskDetailModal, surfacing AI-generated merge commit summaries so users understand when and why tasks landed
- New `ai-summarize` module in core with structured commit summarization logic and tests
- Extend CLI `fn task show` with provenance output
- Refactor merger to produce cleaner merge commit messages with task context
- Update SettingsModal to expose AI summarization toggle (hidden behind feature flag)
- Adjust QuickChatFAB styling for theme compatibility
- Update scheduler and node-routing policy tests to match new behavior
- Add changeset for `@runfusion/fusion` minor release

Commits merged:
- feat(FN-2924): display task provenance in dashboard and cli
- feat(FN-2971): merge fusion/fn-2971
- feat(FN-2947): merge fusion/fn-2947
- feat(FN-2970): merge fusion/fn-2970
- feat(FN-2956): merge fusion/fn-2956

Files changed:
.changeset/add-ai-merge-commit-summary.md          |   5 +
 docs/cli-reference.md                              |   3 +-
 docs/settings-reference.md                         |   3 +
 packages/cli/src/commands/__tests__/task.test.ts   |  44 ++++-
 packages/cli/src/commands/task.ts                  |  55 +++++++
 packages/core/src/__tests__/ai-summarize.test.ts   |  64 ++++++++
 packages/core/src/ai-summarize.ts                  | 114 +++++++++++++
 packages/core/src/index.ts                         |   3 +
 packages/core/src/settings-schema.ts               |   1 +
 packages/core/src/types.ts                         |   4 +
 packages/dashboard/app/components/QuickChatFAB.css |  17 +-
 packages/dashboard/app/components/QuickChatFAB.tsx |   2 +-
 .../dashboard/app/components/SettingsModal.css     |  11 +-
 .../dashboard/app/components/SettingsModal.tsx     |  22 ++-
 .../dashboard/app/components/TaskDetailModal.css   |  40 +++++
 .../dashboard/app/components/TaskDetailModal.tsx   |  82 +++++++++-
 .../__tests__/SettingsModalNodeRouting.test.tsx    |  12 +-
 .../components/__tests__/TaskDetailModal.test.tsx  |  81 ++++++++-
 packages/engine/src/__tests__/merger.test.ts       |  75 +++++++++
 .../src/__tests__/node-routing-policy.test.ts      |  25 ++-
 .../src/__tests__/scheduler-node-routing.test.ts   |  18 +-
 packages/engine/src/merger.ts                      | 181 +++++++++------------
 packages/engine/src/scheduler.ts                   |   8 +-
 23 files changed, 723 insertions(+), 147 deletions(-)

Fusion-Task-Id: FN-2924

packages/dashboard/app/components/TaskDetailModal.css

@@ -115,6 +115,46 @@
   margin-bottom: var(--space-lg);
 }
 
+.detail-provenance {
+  display: flex;
+  align-items: center;
+  gap: var(--space-xs);
+  margin-top: var(--space-sm);
+  margin-bottom: var(--space-sm);
+  color: var(--text-muted);
+}
+
+.detail-provenance svg {
+  width: 1em;
+  height: 1em;
+}
+
+.detail-provenance-link {
+  padding: 0;
+  border: 0;
+  background: transparent;
+  color: var(--todo);
+  cursor: pointer;
+  text-decoration: none;
+  font: inherit;
+}
+
+.detail-provenance-link:hover {
+  text-decoration: underline;
+}
+
+.detail-provenance-link:focus-visible {
+  outline: none;
+  box-shadow: var(--focus-ring-strong);
+  border-radius: var(--radius-sm);
+}
+
+@media (max-width: 768px) {
+  .detail-provenance {
+    align-items: flex-start;
+  }
+}
+
 .detail-priority-chip {
   display: inline-flex;
   align-items: center;