feat(psa): add member mapping CRUD and auto-match endpoints

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

backend/app/schemas/psa_connection.py

@@ -106,3 +106,34 @@ class PsaPostLogResponse(BaseModel):
     status_changed_to: str | None = None
     posted_at: str
     content_preview: str  # first 200 chars
+
+
+# ── Member mapping schemas ───────────────────────────────────────
+
+
+class PsaMemberMappingResponse(BaseModel):
+    id: str
+    user_id: str
+    user_email: str
+    user_name: str
+    external_member_id: str
+    external_member_name: str
+    matched_by: str
+
+
+class PsaMemberMappingSaveRequest(BaseModel):
+    user_id: str
+    external_member_id: str
+    external_member_name: str
+
+
+class PsaMemberResponse(BaseModel):
+    id: str
+    identifier: str
+    name: str
+    email: str | None = None
+
+
+class AutoMatchResult(BaseModel):
+    matched: list[PsaMemberMappingResponse]
+    unmatched_users: int