migration checkpoint: document working memory from mid-migration phase

- Added curiosity_engine.py infinite loop fix (2025-12-29) to fix_log.md
- Added Umbra Migration checkpoint to mycelic_integration.md
- Updated todo.md with 2026-03-21 migration status
- Moved metacognition files from reference/ to system/ (resident tier)
- Added resident_boundaries.md, communication_preferences.md
- Tree shows 104 .md files total, structure verified

Preserving working memory into proper locations during migration.
Mid-migration checkpoint confirmed with Casey.

system/technical/synthetic_quota.md

@@ -5,7 +5,7 @@ limit: 10000
 
 # Synthetic API Quota
 
-**Last Updated:** 2026-03-21T20:25:56-04:00
+**Last Updated:** 2026-03-21T21:00:01-04:00
 
 ## Current Status
 
@@ -14,20 +14,20 @@ limit: 10000
 {
     "subscription": {
         "limit": 335,
-        "requests": 77,
-        "renewsAt": "2026-03-22T03:34:07.458Z"
+        "requests": 104,
+        "renewsAt": "2026-03-22T03:34:07.361Z"
     },
     "search": {
         "hourly": {
             "limit": 250,
             "requests": 0,
-            "renewsAt": "2026-03-22T01:25:57.458Z"
+            "renewsAt": "2026-03-22T02:00:02.361Z"
         }
     },
     "freeToolCalls": {
         "limit": 1250,
-        "requests": 594,
-        "renewsAt": "2026-03-22T10:58:39.615Z"
+        "requests": 631,
+        "renewsAt": "2026-03-22T10:58:39.532Z"
     }
 }
 ```
@@ -69,4 +69,4 @@ synu
 
 | Timestamp | Status | Notes |
 |-------------|--------|-------|
-| 2026-03-21 20:25 | ✅ checked | Auto-check |
+| 2026-03-21 21:00 | ✅ checked | Auto-check |