fix: route all agent loopback calls through internal_api_base() helper (#3322)

#2753 made the agent loopback base port-configurable but only for
_COOKBOOK_BASE in tool_implementations. Several other in-process loopback
calls still hardcoded http://localhost:7000 and broke off port 7000:
cookbook_serve_lifecycle (model-endpoints x2, shell/exec), builtin_actions
(model/serve), task_routes (calendar x3), and the gallery/email calls in
tool_implementations.

Extract the resolution (ODYSSEUS_INTERNAL_BASE / APP_PORT / 7000 fallback,
127.0.0.1 to avoid IPv6 ambiguity) into core.constants.internal_api_base()
and route every call site through it. Rename the now-misnamed _COOKBOOK_BASE
to _INTERNAL_BASE since it serves gallery/email/calendar/serve too. Adds a
test for the resolver plus a regression guard against reintroducing the
literal.

Part of #2752.

Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>

core/constants.py

@@ -38,3 +38,22 @@ CLEANUP_INTERVAL_HOURS = int(os.getenv("CLEANUP_INTERVAL_HOURS", "24"))
 # Default parameters
 DEFAULT_TEMPERATURE = 1.0
 DEFAULT_MAX_TOKENS = 0
+
+
+def internal_api_base() -> str:
+    """Base URL for in-process loopback calls to Odysseus's own API.
+
+    Agent tools and background jobs reach admin-gated routes by calling the
+    running server over HTTP. Resolution order:
+      1. ODYSSEUS_INTERNAL_BASE  - explicit override (e.g. behind a TLS proxy).
+      2. APP_PORT                - http://127.0.0.1:$APP_PORT (docker-compose).
+      3. Fallback http://127.0.0.1:7000 - legacy default.
+
+    127.0.0.1 (not "localhost") avoids IPv6/DNS ambiguity for a strictly-local
+    call. Without this, loopback tools fail with "All connection attempts
+    failed" whenever the server is not on port 7000.
+    """
+    override = os.environ.get("ODYSSEUS_INTERNAL_BASE")
+    if override:
+        return override.rstrip("/")
+    return f"http://127.0.0.1:{os.environ.get('APP_PORT', '7000')}"