feat(ai): add per-character AI model assignment and identity profiles

Implements deterministic model resolution (column → env map → pool →
default) and adds AI identity fields to characters. Migration backfills
existing rows with deterministic defaults. Controller uses resolved model
and identity block in system prompts for contextual conversations.

tests/Feature/PersonTalkTest.php

@@ -2,6 +2,7 @@
 
 namespace Tests\Feature;
 
+use App\Http\Controllers\Web\PersonTalkController;
 use App\Models\AiAgent;
 use App\Models\Character;
 use App\Models\PersonTalk;
@@ -521,4 +522,121 @@ class PersonTalkTest extends TestCase
         $this->assertNotNull($reply);
         $this->assertSame('Praça fechada para obra, já passa.', $reply->body);
     }
+
+    /**
+     * Model resolution priority: column → env map (id/name) → pool slot,
+     * always inside the allow-list (RULES.md 2.1) and stable per id.
+     */
+    public function test_model_resolution_priority_and_allow_list(): void
+    {
+        $mapped = 'openrouter/free';
+        $pooled = 'nvidia/nemotron-3.5-lightning:free';
+
+        config([
+            'ai.models' => [$pooled, $mapped],
+            'ai.character_models' => [
+                'maria' => $mapped,
+                '7' => $pooled,
+                'bad' => 'not/allowed-model',
+            ],
+        ]);
+
+        // 1) Character column wins over everything.
+        $this->assertSame(
+            $mapped,
+            PersonTalkController::resolveModel($mapped, 'Qualquer', 99)
+        );
+
+        // 2) Env map by name (case-insensitive) and by id.
+        $this->assertSame($mapped, PersonTalkController::resolveModel(null, 'Maria', 3));
+        $this->assertSame($pooled, PersonTalkController::resolveModel(null, 'Outro', 7));
+
+        // 3) Non allow-listed entries are ignored → deterministic pool slot.
+        $fromPool = PersonTalkController::resolveModel('not/allowed-model', 'Bad', 4);
+        $this->assertContains($fromPool, [$pooled, $mapped]);
+        $this->assertNotSame('not/allowed-model', $fromPool);
+
+        // 4) Empty map/pool falls back to the allow-listed default.
+        config(['ai.character_models' => [], 'ai.models' => []]);
+        $default = config('ai.default_model');
+        $this->assertContains($default, config('ai.allowed_models'));
+        $this->assertSame($default, PersonTalkController::resolveModel(null, 'X', 1));
+
+        // 5) Same character always resolves to the same model.
+        config(['ai.models' => [$pooled, $mapped]]);
+        $stable = PersonTalkController::resolveModel(null, 'Estável', 5);
+        $this->assertSame($stable, PersonTalkController::resolveModel(null, 'Estável', 5));
+    }
+
+    /**
+     * The identity/personality profile and the resolved model travel in
+     * the upstream payload while registration data stays out (RULES.md 2.2).
+     */
+    public function test_identity_and_model_flow_into_upstream_payload(): void
+    {
+        config([
+            'ai.openrouter.api_key' => 'test-key',
+            'ai.models' => ['liquid/lfm-2.5-2.6b:free'],
+            'ai.character_models' => [],
+        ]);
+
+        Http::fake([
+            'openrouter.ai/*' => Http::response([
+                'choices' => [['message' => ['content' => 'Oi! Tudo tranquilo na cidade.']]],
+            ]),
+        ]);
+
+        [$userA, $me] = $this->makeCitizen();
+        [$userB, $them] = $this->makeCitizen();
+
+        $them->update([
+            'ai_age' => 34,
+            'ai_gender' => 'feminino',
+            'ai_personality' => 'Extrovertido e curiosa, adora puxar conversa.',
+            'ai_bio' => 'Moradora do centro, vive nas novidades do bairro.',
+        ]);
+
+        $this->actingAs($userA)
+            ->postJson('/talk/person', [
+                'kind' => 'character',
+                'peer' => $them->id,
+                'message' => 'Oi, tudo bem?',
+            ])
+            ->assertCreated();
+
+        $peerEmail = $userB->email;
+        $peerName = $them->name;
+        Http::assertSent(function ($request) use ($peerEmail, $peerName): bool {
+            $payload = $request->data();
+            $encoded = json_encode($payload, JSON_UNESCAPED_UNICODE);
+            $system = (string) ($payload['messages'][0]['content'] ?? '');
+
+            return $payload['model'] === 'liquid/lfm-2.5-2.6b:free'
+                && str_contains($system, 'Idade: 34')
+                && str_contains($system, 'Sexo: feminino')
+                && str_contains($system, 'Extrovertido e curiosa')
+                && str_contains($system, 'Moradora do centro')
+                && str_contains($system, 'Nome: '.$peerName)
+                && ! str_contains($encoded, $peerEmail);
+        });
+
+        // The reply from the fake model is stored normally.
+        $this->assertNotNull(PersonTalk::query()
+            ->where('from_character_id', $them->id)
+            ->where('body', 'Oi! Tudo tranquilo na cidade.')
+            ->first());
+    }
+
+    /**
+     * Fresh citizens are created with a ready-to-use default persona.
+     */
+    public function test_new_characters_receive_default_persona(): void
+    {
+        [, $character] = $this->makeCitizen();
+
+        $this->assertNotNull($character->ai_age);
+        $this->assertGreaterThanOrEqual(18, $character->ai_age);
+        $this->assertLessThanOrEqual(68, $character->ai_age);
+        $this->assertContains($character->ai_personality, Character::AI_PERSONALITIES);
+    }
 }