feat(vocero): add linked content and TALKFIRST greetings (#2)

Opening a report or podcast link now establishes an authenticated starting reference for the conversation. Users can select other accessible content or compare reports while retaining the original link, and TALKFIRST greetings can name the verified report or podcast.

Release notes:

- Added authenticated report and episode link resolution with bounded lookups and unavailable-content handling
- Added explicit conversation selection without restricting searches or changing the reference during comparisons
- Added contextual TALKFIRST greetings through both voice-proxy and HTTP reasoning paths
- Preserved backend permission checks, conversation isolation, cancellation, and the existing speech protocol

Reviewed-on: AquaPortal/s2s#2

vocero-api/vocero_api/api/routes/conversations.py

@@ -6,8 +6,8 @@ from fastapi import APIRouter, HTTPException, Request, Response
 
 from vocero_api.core import config as settings
 from vocero_api.models.mcp import ConversationRequest, ConversationResponse, IntegrationError, McpCatalogResponse
-from vocero_api.providers import backend_login, mcp
-from vocero_api.services import conversations
+from vocero_api.providers import backend_login
+from vocero_api.services import content_context, conversations
 
 router = APIRouter()
 
@@ -23,8 +23,11 @@ async def create_conversation(body: ConversationRequest, request: Request, respo
     try:
         conversations.check_origin(request)
         login = await backend_login.login(body.phoneNumber.strip())
+        linked_content = await content_context.from_link(
+            login.sessionToken.get_secret_value(), body.report_id, body.episode_id
+        )
         browser = request.cookies.get(conversations.COOKIE_NAME) or secrets.token_urlsafe(32)
-        item = conversations.store.create(browser, login)
+        item = conversations.store.create(browser, login, linked_content)
     except IntegrationError as exc:
         raise HTTPException(exc.status, exc.message) from None
     response.set_cookie(
@@ -69,7 +72,7 @@ async def list_tools(request: Request, response: Response) -> McpCatalogResponse
     item: conversations.Conversation | None = None
     try:
         item = conversations.resolve(request)
-        catalog = await mcp.discover(item.backend_token)
+        catalog = await content_context.catalog(item.backend_token)
         item.require_active()
         item.catalog = catalog
         response.headers["Cache-Control"] = "no-store"