feat: rename project to InboxConverge with configurable contact details

Agent-Logs-Url: https://github.com/christianlouis/pop_puller_to_gmail/sessions/82f2f361-3513-44e6-991b-db1a19902772

Co-authored-by: christianlouis <361235+christianlouis@users.noreply.github.com>

docs/adr/002-fernet-encryption.md

@@ -126,7 +126,7 @@ elif version == 'v2':
 def get_or_create_user_salt(user_id: int) -> bytes:
     # Use deterministic salt based on user_id + global salt
     # OR store random salt in database per user
-    return hashlib.sha256(f'pop3_forwarder_user_{user_id}'.encode()).digest()
+    return hashlib.sha256(f'inbox_converge_user_{user_id}'.encode()).digest()
 ```
 
 ## Security Best Practices

docs/adr/003-fastapi-web-framework.md

@@ -64,7 +64,7 @@ async def lifespan(app: FastAPI):
     # Shutdown: cleanup
 
 app = FastAPI(
-    title="POP3 Forwarder API",
+    title="InboxConverge API",
     lifespan=lifespan,
     openapi_url="/api/openapi.json",
     docs_url="/api/docs",