fix(types): drop safesearch schema default so omitted value uses instance default (BUG-006)

Post-review (Codacy + Copilot): the safesearch schema's `default: "0"` can
cause some MCP clients to auto-fill "0" and override the operator/instance
default (SEARXNG_DEFAULT_SAFESEARCH or the SearXNG instance default), which
contradicts the documented "default: instance setting" behavior. Remove the
schema default — an omitted safesearch now reaches the server as undefined and
the instance/operator default applies. Tests updated to assert no default is
present. type:"string" and enum:["0","1","2"] unchanged.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Co-Authored-By: Codex <noreply@openai.com>

Author: 3 people

__tests__/integration/mcp-handlers.test.ts

@@ -163,7 +163,8 @@ async function runTests() {
     const safesearchSchema = searchProps.safesearch as Record<string, unknown>;
     assert.equal(safesearchSchema.type, 'string');
     assert.deepEqual(safesearchSchema.enum, ['0', '1', '2']);
-    assert.equal(safesearchSchema.default, '0');
+    assert.equal(safesearchSchema.default, undefined);
+    assert.ok(!Object.hasOwn(safesearchSchema, 'default'));
     assert.ok(!(safesearchSchema.enum as unknown[]).some((value) => typeof value === 'number'));
 
     const suggestionsTool = result.tools.find((t) => t.name === 'searxng_search_suggestions');

__tests__/unit/types.test.ts

@@ -83,7 +83,8 @@ async function runTests() {
     assert.ok(properties.time_range.enum.includes('week'));
     assert.equal(properties.safesearch.type, 'string');
     assert.deepEqual(properties.safesearch.enum, ['0', '1', '2']);
-    assert.equal(properties.safesearch.default, '0');
+    assert.equal(properties.safesearch.default, undefined);
+    assert.ok(!Object.hasOwn(properties.safesearch, 'default'));
     assert.ok(!properties.safesearch.enum.some((value: unknown) => typeof value === 'number'));
     assert.equal(properties.min_score.type, 'number');
     assert.equal(properties.min_score.minimum, 0);

src/types.ts

@@ -216,7 +216,6 @@ export const WEB_SEARCH_TOOL: Tool = {
         description:
           "Safe search filter level (0: None, 1: Moderate, 2: Strict)",
         enum: ["0", "1", "2"],
-        default: "0",
       },
       min_score: {
         type: "number",