feat(honcho): wizard cadence default 2, surface reasoning level, backwards-compat fallback

Setup wizard now always writes dialecticCadence=2 on new configs and
surfaces the reasoning level as an explicit step with all five options
(minimal / low / medium / high / max), always writing
dialecticReasoningLevel.

Code keeps a backwards-compat fallback of 1 when dialecticCadence is
unset so existing honcho.json configs that predate the setting keep
firing every turn on upgrade. New setups via the wizard get 2
explicitly; docs show 2 as the default.

Also scrubs editorial lines from code and docs ("max is reserved for
explicit tool-path selection", "Unset → every turn; wizard pre-fills 2",
and similar process-exposing phrasing) and adds an inline link to
app.honcho.dev where the server-side observation sync is mentioned in
honcho.md. Recommended cadence range updated to 1-5 across docs and
wizard copy.

tests/honcho_plugin/test_session.py

@@ -865,8 +865,10 @@ class TestDialecticCadenceDefaults:
         _settle_prewarm(provider)
         return provider
 
-    def test_default_is_1(self):
-        """Default dialectic_cadence is 1 — fires every turn unless overridden."""
+    def test_unset_falls_back_to_1(self):
+        """Unset dialecticCadence falls back to 1 (every turn) for backwards
+        compatibility with existing configs that predate the setting. The
+        setup wizard writes 2 explicitly on new configs."""
         provider = self._make_provider()
         assert provider._dialectic_cadence == 1
 
@@ -1569,8 +1571,7 @@ class TestDialecticLifecycleSmoke:
 
 class TestReasoningHeuristic:
     """Char-count heuristic that scales the auto-injected reasoning level by
-    query length, clamped at reasoning_level_cap. 'max' is reserved for
-    explicit tool-path selection."""
+    query length, clamped at reasoning_level_cap."""
 
     @staticmethod
     def _make_provider(cfg_extra=None):