Fix mypy strict type-checking errors

- Add type parameters to bare dict returns (facilitator, lineage, routes)
- Cast response.body to bytes to resolve bytes|memoryview union
- Use separate variables for PlainTextResponse/JSONResponse branches
  to avoid incompatible assignment types

Author: arun-fairfetch

api/routes.py

@@ -132,16 +132,16 @@ async def fetch_content(
     grant_header = await _issue_grant_for_response(request, result.markdown, url, license_type)
 
     if content_format == ContentFormat.MARKDOWN:
-        response = PlainTextResponse(result.markdown, media_type="text/markdown")
+        md_response = PlainTextResponse(result.markdown, media_type="text/markdown")
         _attach_compliance_headers(
-            response,
+            md_response,
             signer=signer,
             content=result.markdown,
             license_type=license_type,
             license_id=grant_header,
         )
-        _attach_preferred_access(response, request)
-        return response
+        _attach_preferred_access(md_response, request)
+        return md_response
 
     summary_result = await summarizer.summarize(result.markdown)
     tracker.record(
@@ -166,19 +166,19 @@ async def fetch_content(
         if grant_header:
             body["fairfetch:usageGrant"] = grant_header
         media = content_format.value
-        response = JSONResponse(content=body, media_type=media)
+        json_response = JSONResponse(content=body, media_type=media)
     else:
-        response = JSONResponse(content=packet.to_jsonld())
+        json_response = JSONResponse(content=packet.to_jsonld())
 
     _attach_compliance_headers(
-        response,
+        json_response,
         signer=signer,
         content=result.markdown,
         license_type=license_type,
         license_id=grant_header,
     )
-    _attach_preferred_access(response, request)
-    return response
+    _attach_preferred_access(json_response, request)
+    return json_response
 
 
 @router.get("/content/summary")
@@ -229,7 +229,7 @@ async def get_markdown(
 
 
 @router.get("/health")
-async def health(request: Request) -> dict:
+async def health(request: Request) -> dict[str, object]:
     scraper_count = getattr(request.app.state, "scraper_intercept_count", 0)
     return {
         "status": "ok",

compliance/lineage.py

@@ -64,7 +64,7 @@ def record(
             )
         )
 
-    def to_dict(self) -> dict:
+    def to_dict(self) -> dict[str, object]:
         return {
             "source_url": self._source_url,
             "pipeline": [r.model_dump() for r in self._records],

interfaces/facilitator.py

@@ -34,7 +34,7 @@ class PaymentRequirement(BaseModel):
     description: str = Field(default="Content access fee")
     extra: dict[str, str] = Field(default_factory=dict)
 
-    def to_402_body(self) -> dict:
+    def to_402_body(self) -> dict[str, object]:
         return {
             "accepts": {
                 "price": self.price,

payments/x402.py

@@ -83,7 +83,7 @@ async def dispatch(self, request: Request, call_next: RequestResponseEndpoint) -
         if self._license_provider:
             body_bytes = b""
             if hasattr(response, "body"):
-                body_bytes = response.body
+                body_bytes = bytes(response.body)
             content_hash = hashlib.sha256(body_bytes).hexdigest() if body_bytes else ""
 
             url_param = request.query_params.get("url", request.url.path)