Add memory-dream skill + additive cross-machine memory sync

memory-dream: read-only memory lint/consolidation analyzer (index, backlinks,
stale refs, dup clusters, profile drift); additive-only --apply-safe, all
merges/deletes are proposals. sync-memory.sh: additive repo<->harness-profile
union (no delete/overwrite, conflicts surfaced), wired to a SessionStart hook.
Migrates the useful profile-only memories into the synced repo store.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

.claude/settings.json

@@ -29,6 +29,17 @@
           }
         ]
       }
+    ],
+    "SessionStart": [
+      {
+        "hooks": [
+          {
+            "type": "command",
+            "command": "bash -c '[ -f \"${CLAUDE_PROJECT_DIR}/.claude/scripts/sync-memory.sh\" ] && bash \"${CLAUDE_PROJECT_DIR}/.claude/scripts/sync-memory.sh\" || true'",
+            "timeout": 30
+          }
+        ]
+      }
     ]
   }
 }