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.

app/domain/schemas/place_search.py

@@ -0,0 +1,28 @@
+from typing import Literal
+
+from pydantic import BaseModel, ConfigDict, Field
+
+MAX_PLACE_SEARCH_RESULTS = 10
+
+
+class PlaceSearchRequest(BaseModel):
+    model_config = ConfigDict(str_strip_whitespace=True, extra="forbid")
+
+    keyword: str = Field(..., min_length=1, max_length=120)
+
+
+class PlaceSearchItem(BaseModel):
+    id: str = Field(..., min_length=1)
+    name: str = Field(..., min_length=1)
+    address: str
+    longitude: float = Field(..., ge=-180, le=180, allow_inf_nan=False)
+    latitude: float = Field(..., ge=-90, le=90, allow_inf_nan=False)
+    category: str | None = None
+    district: Literal["奉贤区"] = "奉贤区"
+
+
+class PlaceSearchResponse(BaseModel):
+    items: list[PlaceSearchItem] = Field(..., max_length=MAX_PLACE_SEARCH_RESULTS)
+    total: int = Field(..., ge=0, le=MAX_PLACE_SEARCH_RESULTS)
+    truncated: bool = False
+    region: Literal["奉贤区"] = "奉贤区"