refactor(cred_proxy): rename Upstream -> Route, fix tea-login AttributeError

Three leftovers from the manifest refactor:

1. provision/cred_proxy.py:223 referenced u.kind == 'gitea' for the
   tea login count — kind was removed from the runtime class, so any
   bottle with a tea-login route raised AttributeError at provision
   time. Switch to `'tea-login' in r.roles`.

2. The runtime class CredProxyUpstream is renamed to CredProxyRoute
   (its data is a route on the proxy, not an "upstream"; the field
   route.upstream is the upstream URL). Module's own naming now
   aligns with manifest.CredProxyRoute and routes.json.

3. cred_proxy_upstreams_for_bottle -> cred_proxy_routes_for_bottle;
   CredProxyPlan.upstreams -> CredProxyPlan.routes; local
   `upstreams` collections become `routes`. Callers in
   backend.py, launch.py, prepare.py, bottle_plan.py,
   provision/cred_proxy.py, and tests updated.

Also strips lingering `bottle.tokens` references from docstrings
(pipelock.py, cred_proxy.py prepare(), manifest._parse_https_host,
test_pipelock_allowlist.py module doc) and removes dead helpers
from the integration test (the _bottle helper used a tokens field
that no longer parses).

claude_bottle/backend/docker/prepare.py

@@ -93,7 +93,7 @@ def resolve_plan(
     # anthropic-base-url role. Manifest validation enforces the
     # singleton constraint.
     anthropic_route = next(
-        (u for u in cred_proxy_plan.upstreams if "anthropic-base-url" in u.roles),
+        (r for r in cred_proxy_plan.routes if "anthropic-base-url" in r.roles),
         None,
     )
     if spec.forward_oauth_token and anthropic_route is None: