feat(ultraplan-local): v1.6.0 — /ultraresearch-local deep research command

Add /ultraresearch-local for structured research combining local codebase
analysis with external knowledge via parallel agent swarms. Produces research
briefs with triangulation, confidence ratings, and source quality assessment.

New command: /ultraresearch-local with modes --quick, --local, --external, --fg.
New agents: research-orchestrator (opus), docs-researcher, community-researcher,
security-researcher, contrarian-researcher, gemini-bridge (all sonnet).
New template: research-brief-template.md.

Integration: --research flag in /ultraplan-local accepts pre-built research
briefs (up to 3), enriches the interview and exploration phases. Planning
orchestrator cross-references brief findings during synthesis.

Design principle: Context Engineering — right information to right agent at
right time. Research briefs are structured artifacts in the pipeline:
ultraresearch → brief → ultraplan --research → plan → ultraexecute.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

plugins/ultraplan-local/settings.json

@@ -20,5 +20,22 @@
       "enabled": true,
       "statsFile": "ultraplan-stats.jsonl"
     }
+  },
+  "ultraresearch": {
+    "defaultMode": "default",
+    "maxDimensions": 8,
+    "geminiBridge": {
+      "enabled": true,
+      "pollIntervalSeconds": 30,
+      "timeoutMinutes": 25
+    },
+    "interview": {
+      "maxQuestions": 4,
+      "typicalQuestions": 3
+    },
+    "tracking": {
+      "enabled": true,
+      "statsFile": "ultraresearch-stats.jsonl"
+    }
   }
 }