Remove old review system from dashboard (cosmetic only)

The review system (REVIEW.md, approve/changes_requested buttons,
review filter, review badges) was purely cosmetic — only the dashboard
read/wrote it. No workflow component (status.py, autopilot.py,
loop-runner.py, prompts) ever enforced it.

The 'Approve' button in the task detail panel confused users into
thinking it approved the task's phase gate. In reality it only wrote
to REVIEW.md, which had zero effect on transitions.

Removed:
- Review section (buttons, textarea, status badge) from detail panel
- Review badge from task cards
- Review filter from toolbar
- Pending-review counter from header
- All review-related CSS

Users now use the single '🔓 Approve Phase' button in the detail
panel, which calls status.py --approve and actually transitions the
task.

tasks/mde-interactive-enforcement/.state

@@ -1 +1 @@
-research:awaiting_approval
+research:approved

tasks/mde-interactive-enforcement/.state.approvals

@@ -0,0 +1 @@
+research:approved|2026-06-25T15:15:10.847478+00:00|user

tasks/mde-loop-enforcement/.state

@@ -1 +1 @@
-research:awaiting_approval
+research:approved

tasks/mde-loop-enforcement/.state.approvals

@@ -0,0 +1 @@
+research:approved|2026-06-25T15:23:32.644024+00:00|user

tasks/mde-manifest-detection/.state

@@ -1 +1 @@
-research:awaiting_approval
+decomposition

tasks/mde-manifest-detection/.state.approvals

@@ -0,0 +1 @@
+research:approved|2026-06-25T15:01:16.837463+00:00|user