Wake word sensitivity (#207)

## Summary
- Introduces configurable wake word and stop word sensitivity
- Adds UI-controllable thresholds for wake word detection
- Refactors wake word loading and handling logic
- Improves audio preprocessing and runtime behavior

## Key Features
- Per-wake-word sensitivity configuration (Wake Word 1 & 2)
- Configurable stop word sensitivity
- Fine-grained numeric control (0.0 – 1.0, step 0.001)
- Sensitivity values exposed as Number Entities for Home Assistant
- Persistent storage of user-defined sensitivity values

## Wake Word Handling
- Support for model-specific default thresholds (`probability_cutoff`)
- Automatic fallback to defaults if no user value is set
- Separate thresholds for:
  - Wake Word 1
  - Wake Word 2
  - Stop Word
- Unified handling for MicroWakeWord and OpenWakeWord models

## UI / API Integration
- Adds new Home Assistant entities:
  - `WakeWord1SensitivityNumberEntity`
  - `WakeWord2SensitivityNumberEntity`
  - `StopWordSensitivityNumberEntity`
- Entities support:
  - Live updates
  - Persistence via preferences
  - Synchronization with runtime state
- Pushes updated values to Home Assistant on startup

## Refactoring
- Extracted wake word logic into `wake_word.py`
  - Model discovery
  - Model loading
  - Stop word handling
- Simplified `__main__.py` by delegating wake word responsibilities
- Improved separation between configuration and runtime state

## Additional Changes
- Improved debug logging across initialization and runtime

## Impact
- Enables fine-tuning of wake word detection accuracy
- Reduces false positives and missed triggers
- Improves usability via UI-based configuration
- Provides better flexibility across different environments and microphones

docker-compose.dev.yml

@@ -2,7 +2,7 @@
 services:
   # Fix permissions for wakeword_data and configuration volume
   fix-permissions:
-    image: "ghcr.io/ohf-voice/linux-voice-assistant:latest"
+    image: "ghcr.io/ohf-voice/linux-voice-assistant-pr:207"
     entrypoint: []
     command: "chown -R ${LVA_USER_ID:-1000}:${LVA_USER_GROUP:-1000} /app/local /app/configuration /app/wakewords/custom /app/sounds/custom"
     environment:
@@ -24,7 +24,7 @@ services:
   # Linux Voice Assistant
   linux-voice-assistant:
     container_name: linux-voice-assistant
-    image: "ghcr.io/ohf-voice/linux-voice-assistant:latest"
+    image: "ghcr.io/ohf-voice/linux-voice-assistant-pr:207"
     restart: unless-stopped
     network_mode: "host"
     user: "${LVA_USER_ID:-1000}:${LVA_USER_GROUP:-1000}"
@@ -66,7 +66,9 @@ services:
       timeout: 5s
       retries: 3
       start_period: 90s
-    #command:
+    command:
+      - "--mic-noise-suppression"
+      - "1"
     #  - --additional-parameters-here
     #  - --but-use-env-if-possible