feat(server): integrate MCP queries and investigation messaging

Add project-bound OAuth MCP queries and controlled analysis with scoped evidence,
limits, timeouts and a nearby-model spatial query using EPSG:4326 inputs.
Default nearby searches to 200 meters and five results.

Integrate investigation messaging/presentation, health/readiness and typed history;
remove duplicate web search and fix online simulation and compressed baseline writes.
Include project migrations 023-025; keep local credentials and demo seeding excluded.

Validation: 319 focused pytest checks; real PostGIS temporary-table regression;
read-only Jinqian bridge radius comparison; cross-language MCP discovery/calls.

resources/sql/024_agent_messages.sql

@@ -0,0 +1,42 @@
+-- Private messages are deliberately excluded from the project event log.
+BEGIN;
+
+CREATE TABLE IF NOT EXISTS workbench.agent_messages (
+    project_id uuid NOT NULL,
+    message_id uuid NOT NULL,
+    request_id uuid NOT NULL,
+    task_id uuid NOT NULL,
+    run_id uuid NOT NULL,
+    source_session_id text NOT NULL CHECK (length(source_session_id)>0),
+    source_owner_id uuid NOT NULL,
+    conversation_owner_id uuid NOT NULL,
+    target_session_id text,
+    direction text NOT NULL CHECK (direction IN ('to_task','to_chat')),
+    in_reply_to uuid,
+    text text NOT NULL CHECK (length(text) BETWEEN 1 AND 12000 AND text ~ '\S'),
+    status text NOT NULL CHECK (status IN ('pending','enqueued','delivered','failed')),
+    native_message_id text NOT NULL,
+    failure_detail text,
+    created_at timestamptz NOT NULL,
+    updated_at timestamptz NOT NULL,
+    delivered_at timestamptz,
+    PRIMARY KEY (project_id,message_id),
+    UNIQUE (project_id,source_owner_id,source_session_id,request_id),
+    FOREIGN KEY (project_id,task_id)
+        REFERENCES workbench.operational_tasks(project_id,task_id),
+    FOREIGN KEY (project_id,run_id)
+        REFERENCES workbench.operational_task_runs(project_id,run_id),
+    FOREIGN KEY (project_id,in_reply_to)
+        REFERENCES workbench.agent_messages(project_id,message_id),
+    CHECK ((direction='to_task')
+        OR (direction='to_chat' AND in_reply_to IS NOT NULL AND target_session_id IS NOT NULL))
+);
+CREATE INDEX IF NOT EXISTS agent_messages_pending_idx
+    ON workbench.agent_messages(project_id,created_at,message_id)
+    WHERE status IN ('pending','enqueued');
+CREATE INDEX IF NOT EXISTS agent_messages_owner_session_idx
+    ON workbench.agent_messages(project_id,conversation_owner_id,created_at);
+CREATE INDEX IF NOT EXISTS agent_messages_run_idx
+    ON workbench.agent_messages(project_id,run_id,status);
+
+COMMIT;