feat: choose per tool whether MCP, voice or both offer it

src/tools/surfaces.js lists the tools a surface leaves out, and the MCP
server, the voice session's tool list and the browser catalog voice calls
all filter through it. Voice leaves out tools that answer with images, link
to the app, or repeat what its app actions already answer.

src/tools/surfaces.test.mjs

@@ -0,0 +1,50 @@
+import assert from 'node:assert/strict';
+import test from 'node:test';
+import { TOOL_SURFACES, coreTools, toolsForSurface } from './index.js';
+
+const names = (tools) => tools.map((tool) => tool.name);
+
+test('MCP offers every tool and voice leaves out the table entries', () => {
+  assert.deepEqual(names(toolsForSurface(coreTools, 'mcp')), names(coreTools));
+  const voice = names(toolsForSurface(coreTools, 'voice'));
+  assert.equal(
+    voice.length,
+    coreTools.length - Object.keys(TOOL_SURFACES).length,
+  );
+  for (const name of Object.keys(TOOL_SURFACES))
+    assert.ok(!voice.includes(name), name);
+  assert.ok(voice.includes('get_weather'));
+  assert.ok(voice.includes('military_awareness'));
+});
+
+test('overrides turn a tool on or off for one surface', () => {
+  const voice = names(
+    toolsForSurface(coreTools, 'voice', {
+      get_weather_map: { voice: true },
+      get_weather: { voice: false },
+    }),
+  );
+  assert.ok(voice.includes('get_weather_map'));
+  assert.ok(!voice.includes('get_weather'));
+  assert.ok(
+    !names(
+      toolsForSurface(coreTools, 'mcp', { get_weather: { mcp: false } }),
+    ).includes('get_weather'),
+  );
+});
+
+test('unknown surfaces and tool names are rejected', () => {
+  assert.throws(
+    () => toolsForSurface(coreTools, 'email'),
+    /Unknown tool surface/,
+  );
+  assert.throws(
+    () => toolsForSurface(coreTools, 'voice', { get_wether: { voice: false } }),
+    /Unknown tool: get_wether/,
+  );
+  assert.throws(
+    () =>
+      toolsForSurface(coreTools, 'voice', { get_weather: { voise: false } }),
+    /Unknown tool surface for get_weather: voise/,
+  );
+});