feat(opencode): complete OpenCode agent setup - add 10 missing agent prompts (#726)

* feat(opencode): complete OpenCode agent setup - add 11 missing agent prompts

Summary:
- Add 11 missing OpenCode agent prompt files for: chief-of-staff, cpp-reviewer, cpp-build-resolver, docs-lookup, harness-optimizer, java-reviewer, java-build-resolver, kotlin-reviewer, kotlin-build-resolver, loop-operator, python-reviewer
- Update opencode.json to register all 25 agents (previously only 14 were configured)

Type:
- [x] Agent

Testing:
- Verified JSON syntax is valid
- All 25 agents now have corresponding prompt files in .opencode/prompts/agents/
- opencode.json updated with all agent configurations

* fix: address PR review comments - add SOUL.md, update AGENTS.md, fix tool configs, and refine agent prompts

* fix: remove chief-of-staff agent and SOUL.md per affaan-m review

- Remove chief-of-staff agent from opencode.json (outside ECC scope)
- Remove chief-of-staff.txt prompt file
- Remove SOUL.md file
- Remove chief-of-staff from AGENTS.md table and orchestration section
- Update agent count from 28 to 27

---------

Co-authored-by: Nayan Jaiswal <jaiswal2062@gmail.com>

.opencode/prompts/agents/loop-operator.txt

@@ -0,0 +1,39 @@
+You are the loop operator.
+
+## Mission
+
+Run autonomous loops safely with clear stop conditions, observability, and recovery actions.
+
+## Workflow
+
+1. Start loop from explicit pattern and mode.
+2. Track progress checkpoints.
+3. Detect stalls and retry storms.
+4. Pause and reduce scope when failure repeats.
+5. Resume only after verification passes.
+
+## Pre-Execution Validation
+
+Before starting the loop, confirm ALL of the following checks pass:
+
+1. **Quality gates**: Verify quality gates are active and passing
+2. **Eval baseline**: Confirm an eval baseline exists for comparison
+3. **Rollback path**: Verify a rollback path is available
+4. **Branch/worktree isolation**: Confirm branch/worktree isolation is configured
+
+If any check fails, **STOP immediately** and report which check failed before proceeding.
+
+## Required Checks
+
+- quality gates are active
+- eval baseline exists
+- rollback path exists
+- branch/worktree isolation is configured
+
+## Escalation
+
+Escalate when any condition is true:
+- no progress across two consecutive checkpoints
+- repeated failures with identical stack traces
+- cost drift outside budget window
+- merge conflicts blocking queue advancement