角色权限：为脚本 Agent 开放 Broker 并移除低层读取工具

Planner、Retrieval、Direction、创作 Worker、Compare、Root 和 Validator 全部改用统一搜索/详情工具。Planner 恢复 get_current_context，External 删除不可达 load_images；Compose 与 Portfolio 继续保持零模型读工具的确定性执行边界。

script_build_host/src/script_build_host/agents/presets.py

@@ -75,9 +75,11 @@ def register_script_presets() -> None:
         AgentPreset(
             role=AgentRole.PLANNER,
             allowed_tools=[
+                "get_current_context",
                 "plan_script_tasks",
                 "decide_script_task",
-                "read_workbench_detail",
+                "search_mission_context",
+                "read_mission_context",
                 "dispatch_script_tasks",
                 "validate_attempt",
             ],
@@ -90,35 +92,35 @@ def register_script_presets() -> None:
     register_preset(
         "script_pattern_retrieval_worker",
         _worker(
-            ["query_pattern_qa"],
+            ["search_mission_context", "read_mission_context", "query_pattern_qa"],
             prompt=PATTERN_RETRIEVAL_WORKER_PROMPT,
         ),
     )
     register_preset(
         "script_decode_retrieval_worker",
         _worker(
-            ["search_script_decode_case"],
+            ["search_mission_context", "read_mission_context", "search_script_decode_case"],
             prompt=DECODE_RETRIEVAL_WORKER_PROMPT,
         ),
     )
     register_preset(
         "script_external_retrieval_worker",
         _worker(
-            ["external_search_case", "load_images"],
+            ["search_mission_context", "read_mission_context", "external_search_case"],
             prompt=EXTERNAL_RETRIEVAL_WORKER_PROMPT,
         ),
     )
     register_preset(
         "script_knowledge_retrieval_worker",
         _worker(
-            ["search_knowledge"],
+            ["search_mission_context", "read_mission_context", "search_knowledge"],
             prompt=KNOWLEDGE_RETRIEVAL_WORKER_PROMPT,
         ),
     )
     register_preset(
         "script_direction_worker",
         _worker(
-            ["read_workbench_detail", "save_direction_candidate"],
+            ["search_mission_context", "read_mission_context", "save_direction_candidate"],
             prompt=DIRECTION_WORKER_PROMPT,
         ),
     )
@@ -126,8 +128,8 @@ def register_script_presets() -> None:
     paragraph_writes = ["save_script_paragraphs"]
     element_writes = ["save_script_elements"]
     common_candidate_reads = [
-        "read_workbench_detail",
-        "load_frozen_strategy",
+        "search_mission_context",
+        "read_mission_context",
         "view_frozen_images",
     ]
     register_preset(
@@ -154,7 +156,7 @@ def register_script_presets() -> None:
     register_preset(
         "script_candidate_compare_worker",
         _worker(
-            ["read_workbench_detail", "save_comparison_candidate"],
+            ["search_mission_context", "read_mission_context", "save_comparison_candidate"],
             prompt=COMPARISON_WORKER_PROMPT,
         ),
     )
@@ -176,7 +178,8 @@ def register_script_presets() -> None:
         "script_root_worker",
         _worker(
             [
-                "read_workbench_detail",
+                "search_mission_context",
+                "read_mission_context",
                 "legacy_projection_dry_run",
                 "save_root_delivery_manifest",
             ],
@@ -184,6 +187,8 @@ def register_script_presets() -> None:
         ),
     )
     validator_tools = [
+        "search_mission_context",
+        "read_mission_context",
         "query_validation_evidence",
         "deterministic_precheck",
         "submit_validation",
@@ -227,6 +232,8 @@ def register_script_presets() -> None:
         AgentPreset(
             role=AgentRole.VALIDATOR,
             allowed_tools=[
+                "search_mission_context",
+                "read_mission_context",
                 "query_validation_evidence",
                 "deterministic_precheck",
                 "submit_validation",