Harden Exact reconcile and soften post-Generate warm.

Overwrite foreign steps/cfg in sparse patches when the user did not ask for params, and skip the cold-load path when Ollama already has the chat model resident.

Co-authored-by: Cursor <cursoragent@cursor.com>

test/patch.test.js

@@ -123,10 +123,22 @@ describe('session.js', () => {
 
     const explicit = mergeExactParamsForGenerate(
       { generate: true, steps: 12, cfg: 2 },
-      { exact, profiles: exact.profiles, profileName: 'turbo' },
+      { exact, profiles: exact.profiles, profileName: 'turbo', userParamIntent: true },
     );
     assert.equal(explicit.patch.steps, 12);
-    assert.equal(explicit.patch.cfg, 2);
+    assert.equal(explicit.patch.cfg, 2);
+
+    const forced = mergeExactParamsForGenerate(
+      { generate: true, steps: 20, cfg: 7 },
+      {
+        exact: { generation: { steps: 8, cfg: 1 }, profiles: { turbo: { steps: 8, cfg: 1, sigma_shift: 1.15 } } },
+        profiles: { turbo: { steps: 8, cfg: 1, sigma_shift: 1.15 } },
+        profileName: 'turbo',
+        userParamIntent: false,
+      },
+    );
+    assert.equal(forced.patch.steps, 8);
+    assert.equal(forced.patch.cfg, 1);
   });
 
   it('resolveExactProfileDefaults picks raw over generation defaults', () => {