R1: Dashboard 500 fix, Phase 2/7 uncommitted changes

- Fix dashboard 500 when deps disconnected — _gather_state() now returns
  full defaults instead of bare {'connected': False}
- Phase 2: FX param schemas aligned with DSP implementations
- Phase 7: Pipeline routing, preset manager improvements
- Factory presets: cleanup and normalization

Fixes dashboard crash on disconnected state (dogfood issue #1)

presets/factory/bank_1/preset_0.json

@@ -7,9 +7,9 @@
   "chain": [
     {"fx_type": "noise_gate", "enabled": true, "bypass": false, "params": {"threshold": 0.015}, "nam_model_path": "", "ir_file_path": ""},
     {"fx_type": "overdrive", "enabled": true, "bypass": false, "params": {"drive": 0.55, "gain": 0.8}, "nam_model_path": "", "ir_file_path": ""},
-    {"fx_type": "nam_amp", "enabled": true, "bypass": false, "params": {}, "nam_model_path": "factory/marshall_plexi.nam", "ir_file_path": ""},
-    {"fx_type": "ir_cab", "enabled": true, "bypass": false, "params": {}, "nam_model_path": "", "ir_file_path": "factory/greenback_4x12.wav"},
+    {"fx_type": "eq", "enabled": true, "bypass": false, "params": {"bass": 0.6, "mid": 0.4, "treble": 0.7}, "nam_model_path": "", "ir_file_path": ""},
     {"fx_type": "delay", "enabled": true, "bypass": false, "params": {"time": 380.0, "feedback": 0.3, "mix": 0.25}, "nam_model_path": "", "ir_file_path": ""},
+    {"fx_type": "ir_cab", "enabled": true, "bypass": false, "params": {"wet": 1.0, "dry": 0.0}, "nam_model_path": "", "ir_file_path": "~/.pedal/irs/british-4x12.wav"},
     {"fx_type": "volume", "enabled": true, "bypass": false, "params": {"level": 0.75}, "nam_model_path": "", "ir_file_path": ""}
   ],
   "midi_mappings": {