refactor(agents): remove code-index MCP dependencies

Remove references to mcp__code-index MCP tool and simplify context discovery to use native search tools (ripgrep, find) with MCP Exa for external research.

Changes:
- action-planning-agent.md: Remove code-index from capabilities and examples
- cli-execution-agent.md: Remove MCP code-index discovery section, update to use ripgrep/find only
- code-developer.md: Minor documentation updates
- task-json-agent-mode.txt: Remove code-index references
- task-json-cli-mode.txt: Remove code-index references
- workflow-architecture.md: Update MCP integration documentation

Rationale:
- Simplify dependency stack
- Native tools (rg, find) provide sufficient file discovery capabilities
- MCP Exa remains for external research (best practices, documentation)
- Reduces maintenance overhead and improves reliability

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

.claude/workflows/cli-templates/prompts/workflow/task-json-agent-mode.txt

@@ -52,9 +52,12 @@ Task JSON Schema - Agent Mode (No Command Field)
         "on_error": "fail"
       },
       {
-        "step": "mcp_codebase_exploration",
-        "action": "Explore codebase using MCP",
-        "command": "mcp__code-index__find_files(pattern=\"{file_pattern}\") && mcp__code-index__search_code_advanced(pattern=\"{search_pattern}\")",
+        "step": "local_codebase_exploration",
+        "action": "Explore codebase using local search",
+        "commands": [
+          "bash(rg '^(function|class|interface).*{keyword}' --type ts -n --max-count 15)",
+          "bash(find . -name '*{keyword}*' -type f | grep -v node_modules | head -10)"
+        ],
         "output_to": "codebase_structure",
         "on_error": "skip_optional"
       }

.claude/workflows/cli-templates/prompts/workflow/task-json-cli-mode.txt

@@ -52,9 +52,12 @@ Task JSON Schema - CLI Execute Mode (With Command Field)
         "on_error": "fail"
       },
       {
-        "step": "mcp_codebase_exploration",
-        "action": "Explore codebase using MCP",
-        "command": "mcp__code-index__find_files(pattern=\"{file_pattern}\")",
+        "step": "local_codebase_exploration",
+        "action": "Explore codebase using local search",
+        "commands": [
+          "bash(rg '^(function|class|interface).*{keyword}' --type ts -n --max-count 15)",
+          "bash(find . -name '*{keyword}*' -type f | grep -v node_modules | head -10)"
+        ],
         "output_to": "codebase_structure",
         "on_error": "skip_optional"
       }

.claude/workflows/workflow-architecture.md

@@ -343,9 +343,12 @@ The `[FLOW_CONTROL]` marker indicates that a task or prompt contains flow contro
       "on_error": "skip_optional"
     },
     {
-      "step": "mcp_codebase_exploration",
-      "action": "Explore codebase using MCP",
-      "command": "mcp__code-index__find_files(pattern=\"*.ts\") && mcp__code-index__search_code_advanced(pattern=\"auth\")",
+      "step": "local_codebase_exploration",
+      "action": "Explore codebase using local search",
+      "commands": [
+        "bash(rg '^(function|class|interface).*auth' --type ts -n --max-count 15)",
+        "bash(find . -name '*auth*' -type f | grep -v node_modules | head -10)"
+      ],
       "output_to": "codebase_structure"
     }
   ],
@@ -416,7 +419,7 @@ The `[FLOW_CONTROL]` marker indicates that a task or prompt contains flow contro
 **Command Types Supported**:
 - **Bash commands**: `bash(command)` - Any shell command
 - **Tool calls**: `Read(file)`, `Glob(pattern)`, `Grep(pattern)`
-- **MCP tools**: `mcp__code-index__find_files()`, `mcp__exa__get_code_context_exa()`
+- **MCP tools**: `mcp__exa__get_code_context_exa()`, `mcp__exa__web_search_exa()`
 - **CLI commands**: `gemini`, `qwen`, `codex --full-auto exec`
 
 **Example**:
@@ -541,8 +544,6 @@ codex --full-auto exec "task" resume --last --skip-git-repo-check -s danger-full
 - `bash(command)` - Execute bash command
 
 **MCP Tools**:
-- `mcp__code-index__find_files(pattern="*.ts")` - Find files using code index
-- `mcp__code-index__search_code_advanced(pattern="auth")` - Search code patterns
 - `mcp__exa__get_code_context_exa(query="...")` - Get code context from Exa
 - `mcp__exa__web_search_exa(query="...")` - Web search via Exa