refactor(session): modular system prompts and runner wiring

AGENTS.md

@@ -14,25 +14,6 @@
 | LLM 中间推理落盘（workflow 节点内） | `~/.flocks/workspace/outputs/<today>/artifacts/` |
 | 临时调试/草稿文件 | `/tmp/` |
 
-### 代码示例（workflow 节点 / Python 脚本）
-
-```python
-import os, datetime
-from flocks.workspace.manager import WorkspaceManager
-
-# 在执行时动态取当日日期，不依赖 session 启动时的注入值
-ws = WorkspaceManager.get_instance()
-output_dir = str(ws.get_workspace_dir() / 'outputs' / datetime.date.today().isoformat())
-os.makedirs(output_dir, exist_ok=True)
-
-# 写报告
-tool.run('write', filePath=os.path.join(output_dir, 'final_report.md'), content=report)
-# 写 LLM 中间输出
-artifacts_dir = os.path.join(output_dir, 'artifacts')
-os.makedirs(artifacts_dir, exist_ok=True)
-tool.run('write', filePath=os.path.join(artifacts_dir, 'payload_analysis.md'), content=llm_output)
-```
-
 ### 何时可以使用其他路径
 
 - 用户在 prompt 中**明确指定**了输出路径（优先尊重用户指定）
@@ -169,4 +150,4 @@ Rex has a dedicated `flocks_skills` tool for managing agent skills.
 
 ## Important
 - 涉及 `tdp`、`onesec`、`skyeye`、`qingteng` 的任务时，必须先读取并遵循对应的 skill。
-- 对上述系统，禁止绕过对应 skill 直接调用相关 tools；也不要直接使用 `agent-browser`。
+- 对上述系统，禁止绕过对应 skill 直接调用相关 tools；也不要直接使用 `browser`。

flocks/agent/agent_factory.py

@@ -6,7 +6,9 @@
 Resolves each agent to a concrete ``tools`` list. If legacy ``permission`` is
 present, it is expanded against the current tool registry for compatibility.
 If neither ``tools`` nor ``permission`` is declared, the static tool list stays
-empty and runtime exposure falls back to always-load tools only.
+empty and runtime exposure falls back to always-load tools only. ``rex`` is the
+special case: an explicitly empty ``tools: []`` expands to all enabled built-in
+tools so the primary orchestrator keeps broad native capabilities by default.
 
 Extension point:
   Built-in agents:         flocks/agent/agents/<name>/          native=True
@@ -85,6 +87,8 @@ def load_agent(agent_dir: Path, native: bool = False) -> Optional[AgentInfo]:
     Permission is generated from the ``tools`` list in agent.yaml.
     If ``tools`` is absent, the agent keeps an empty static tool list and only
     runtime always-load tools remain available until the session expands them.
+    ``rex`` is the exception: an explicit ``tools: []`` expands to all enabled
+    built-in tools.
 
     Args:
         agent_dir: Path to the agent folder.
@@ -133,7 +137,11 @@ def load_agent(agent_dir: Path, native: bool = False) -> Optional[AgentInfo]:
     # ── Tools / legacy permission compatibility ─────────────────────────────
     tools_list_raw: Optional[List[str]] = raw.get("tools")
     perm_raw = raw.get("permission")
-    tools_list, legacy_permission = resolve_agent_initial_tools(tools_list_raw, perm_raw)
+    tools_list, legacy_permission = resolve_agent_initial_tools(
+        tools_list_raw,
+        perm_raw,
+        agent_name=name,
+    )
 
     # ── Model ────────────────────────────────────────────────────────────────
     model_raw = raw.get("model")
@@ -342,7 +350,11 @@ def yaml_to_agent_info(raw: dict, yaml_path: Path) -> AgentInfo:
     # Tools: prefer new tools list; fall back to old permission dict
     tools_list_raw: Optional[List[str]] = raw.get("tools")
     perm_raw = raw.get("permission")
-    tools_list, legacy_permission = resolve_agent_initial_tools(tools_list_raw, perm_raw)
+    tools_list, legacy_permission = resolve_agent_initial_tools(
+        tools_list_raw,
+        perm_raw,
+        agent_name=name,
+    )
 
     desc_cn = raw.get("description_cn")
     if desc_cn is None and isinstance(raw.get("descriptionCn"), str):

flocks/agent/agents/hephaestus/prompt_builder.py

@@ -44,6 +44,7 @@ def build_hephaestus_prompt(
     use_task_system: bool = False,
 ) -> str:
     from flocks.agent.prompt_utils import (
+        build_agent_selection_table,
         build_key_triggers_section,
         build_tool_selection_table,
         build_explore_section,
@@ -56,7 +57,8 @@ def build_hephaestus_prompt(
     )
 
     key_triggers = build_key_triggers_section(available_agents, available_skills)
-    tool_selection = build_tool_selection_table(available_agents, available_tools, available_skills)
+    tool_selection = build_tool_selection_table([], available_tools, available_skills)
+    agent_selection = build_agent_selection_table(available_agents)
     explore_section = build_explore_section(available_agents)
     librarian_section = build_librarian_section(available_agents)
     category_skills_guide = build_category_skills_delegation_guide(available_categories, available_skills)
@@ -184,6 +186,8 @@ def build_hephaestus_prompt(
 
 __TOOL_SELECTION__
 
+__AGENT_SELECTION__
+
 __EXPLORE_SECTION__
 
 __LIBRARIAN_SECTION__
@@ -235,6 +239,7 @@ def build_hephaestus_prompt(
     prompt = template
     prompt = prompt.replace("__KEY_TRIGGERS__", key_triggers)
     prompt = prompt.replace("__TOOL_SELECTION__", tool_selection)
+    prompt = prompt.replace("__AGENT_SELECTION__", agent_selection)
     prompt = prompt.replace("__EXPLORE_SECTION__", explore_section)
     prompt = prompt.replace("__LIBRARIAN_SECTION__", librarian_section)
     prompt = prompt.replace("__CATEGORY_SKILLS_GUIDE__", category_skills_guide)

flocks/agent/agents/rex/agent.yaml

@@ -6,23 +6,5 @@ mode: primary
 hidden: false
 color: "#00CED1"
 delegatable: false
-tools:
-  - read
-  - list
-  - glob
-  - grep
-  - edit
-  - write
-  - bash
-  - skill
-  - delegate_task
-  - task
-  - todoread
-  - todowrite
-  - run_workflow
-  - run_workflow_node
-  - background_output
-  - background_cancel
-  - session_list
-  - channel_message
+tools: []
 # prompt is left empty – injected dynamically by prompt_builder.py