fix: is_local_endpoint misses Docker/Podman DNS names (#7950)

* fix(tools): neutralize shell injection in _write_to_sandbox via path quoting

_write_to_sandbox interpolated storage_dir and remote_path directly into
a shell command passed to env.execute(). Paths containing shell
metacharacters (spaces, semicolons, $(), backticks) could trigger
arbitrary command execution inside the sandbox.

Fix: wrap both paths with shlex.quote(). Clean paths (alphanumeric +
slashes/hyphens/dots) are left unmodified by shlex.quote, so existing
behavior is unchanged. Paths with unsafe characters get single-quoted.

Tests added for spaces, $(command) substitution, and semicolon injection.

* fix: is_local_endpoint misses Docker/Podman DNS names

host.docker.internal, host.containers.internal, gateway.docker.internal,
and host.lima.internal are well-known DNS names that container runtimes
use to resolve the host machine. Users running Ollama on the host with
the agent in Docker/Podman hit the default 120s stream timeout instead
of the bumped 1800s because these hostnames weren't recognized as local.

Add _CONTAINER_LOCAL_SUFFIXES tuple and suffix check in
is_local_endpoint(). Tests cover all three runtime families plus a
negative case for domains that merely contain the suffix as a substring.

agent/model_metadata.py

@@ -179,6 +179,12 @@ _MAX_COMPLETION_KEYS = (
 
 # Local server hostnames / address patterns
 _LOCAL_HOSTS = ("localhost", "127.0.0.1", "::1", "0.0.0.0")
+# Docker / Podman / Lima DNS names that resolve to the host machine
+_CONTAINER_LOCAL_SUFFIXES = (
+    ".docker.internal",
+    ".containers.internal",
+    ".lima.internal",
+)
 
 
 def _normalize_base_url(base_url: str) -> str:
@@ -254,6 +260,9 @@ def is_local_endpoint(base_url: str) -> bool:
         return False
     if host in _LOCAL_HOSTS:
         return True
+    # Docker / Podman / Lima internal DNS names (e.g. host.docker.internal)
+    if any(host.endswith(suffix) for suffix in _CONTAINER_LOCAL_SUFFIXES):
+        return True
     # RFC-1918 private ranges and link-local
     import ipaddress
     try: