unsloth run: add --enable-tools/--disable-tools server-side tool policy (#5277)

* Add process-level tool_policy state for unsloth run

* Apply tool_policy override at chat/completions, /messages, and tool pass-through gates

* Add pure resolver for unsloth run --enable-tools/--disable-tools

* Wire --enable-tools/--disable-tools into unsloth run

* Color tool-policy notices and confirmation prompt in Claude orange

* Always show tool-status notice; print URL + API key in silent mode

* Treat any non-loopback bind as external; forward --yes after parent prompt

* Fix tool_policy double-module bug: import via state.tool_policy to share global with routes

tests/python/test_unsloth_run_tool_policy_resolver.py

@@ -0,0 +1,201 @@
+# Copyright 2025-present the Unsloth AI Inc. team. All rights reserved.
+
+"""
+Truth-table tests for `resolve_tool_policy` -- the pure resolver behind
+`unsloth run --enable-tools/--disable-tools`.
+
+Covers:
+  - 127.0.0.1 default-on, explicit on, explicit off
+  - 0.0.0.0 default-off, explicit off
+  - 0.0.0.0 + explicit on: confirm prompt unless --silent or --yes,
+    abort on negative answer.
+"""
+
+import pytest
+import typer
+
+from unsloth_cli._tool_policy import is_external_host, resolve_tool_policy
+
+
+def _never_prompt(_msg: str) -> bool:
+    raise AssertionError("prompt should not have been called")
+
+
+def _prompt_yes(_msg: str) -> bool:
+    return True
+
+
+def _prompt_no(_msg: str) -> bool:
+    return False
+
+
+class TestLocalhostHost:
+    @pytest.mark.parametrize("flag", [None, True, False])
+    def test_no_prompt(self, flag):
+        # localhost never prompts regardless of flag
+        result = resolve_tool_policy(
+            host = "127.0.0.1",
+            flag = flag,
+            yes = False,
+            silent = False,
+            prompt = _never_prompt,
+        )
+        assert result is (True if flag in (None, True) else False)
+
+    def test_default_is_on(self):
+        assert (
+            resolve_tool_policy(
+                host = "127.0.0.1",
+                flag = None,
+                yes = False,
+                silent = False,
+                prompt = _never_prompt,
+            )
+            is True
+        )
+
+    def test_explicit_off(self):
+        assert (
+            resolve_tool_policy(
+                host = "127.0.0.1",
+                flag = False,
+                yes = False,
+                silent = False,
+                prompt = _never_prompt,
+            )
+            is False
+        )
+
+
+class TestZeroHost:
+    def test_default_is_off(self):
+        assert (
+            resolve_tool_policy(
+                host = "0.0.0.0",
+                flag = None,
+                yes = False,
+                silent = False,
+                prompt = _never_prompt,
+            )
+            is False
+        )
+
+    def test_explicit_off_no_prompt(self):
+        assert (
+            resolve_tool_policy(
+                host = "0.0.0.0",
+                flag = False,
+                yes = False,
+                silent = False,
+                prompt = _never_prompt,
+            )
+            is False
+        )
+
+    def test_explicit_on_silent_skips_prompt(self):
+        assert (
+            resolve_tool_policy(
+                host = "0.0.0.0",
+                flag = True,
+                yes = False,
+                silent = True,
+                prompt = _never_prompt,
+            )
+            is True
+        )
+
+    def test_explicit_on_yes_skips_prompt(self):
+        assert (
+            resolve_tool_policy(
+                host = "0.0.0.0",
+                flag = True,
+                yes = True,
+                silent = False,
+                prompt = _never_prompt,
+            )
+            is True
+        )
+
+    def test_explicit_on_prompt_yes(self):
+        assert (
+            resolve_tool_policy(
+                host = "0.0.0.0",
+                flag = True,
+                yes = False,
+                silent = False,
+                prompt = _prompt_yes,
+            )
+            is True
+        )
+
+    def test_explicit_on_prompt_no_aborts(self):
+        with pytest.raises(typer.Exit) as exc_info:
+            resolve_tool_policy(
+                host = "0.0.0.0",
+                flag = True,
+                yes = False,
+                silent = False,
+                prompt = _prompt_no,
+            )
+        assert exc_info.value.exit_code == 1
+
+
+class TestIsExternalHost:
+    @pytest.mark.parametrize(
+        "host", ["127.0.0.1", "localhost", "::1", "LOCALHOST", "Localhost"]
+    )
+    def test_loopback_aliases_are_local(self, host):
+        assert is_external_host(host) is False
+
+    @pytest.mark.parametrize(
+        "host", ["0.0.0.0", "::", "192.168.1.5", "10.0.0.1", "example.com"]
+    )
+    def test_non_loopback_is_external(self, host):
+        assert is_external_host(host) is True
+
+
+class TestSpecificNetworkIP:
+    """Binding to a specific LAN IP must follow the same rules as 0.0.0.0."""
+
+    def test_default_is_off(self):
+        assert (
+            resolve_tool_policy(
+                host = "192.168.1.5",
+                flag = None,
+                yes = False,
+                silent = False,
+                prompt = _never_prompt,
+            )
+            is False
+        )
+
+    def test_explicit_on_prompts(self):
+        seen = []
+
+        def _prompt(msg: str) -> bool:
+            seen.append(msg)
+            return True
+
+        assert (
+            resolve_tool_policy(
+                host = "192.168.1.5",
+                flag = True,
+                yes = False,
+                silent = False,
+                prompt = _prompt,
+            )
+            is True
+        )
+        assert any("192.168.1.5" in m for m in seen)
+
+    def test_localhost_alias_does_not_prompt(self):
+        assert (
+            resolve_tool_policy(
+                host = "localhost",
+                flag = True,
+                yes = False,
+                silent = False,
+                prompt = _never_prompt,
+            )
+            is True
+        )