Add time-window based recording retention

Adds ability to filter recordings by time windows after a configurable
retention period. Useful for reducing storage while keeping recordings
during relevant times (e.g., business hours).

New config options under record.motion (and record.continuous):
- days: maximum retention in days (null for unlimited, 0 for none)
- hours: list of time windows like "mon-fri 07:00-18:00"
- always_retain: hours to keep all recordings before filtering (default 24)

Recordings associated with alerts/detections are always retained
regardless of time windows.

docs/docs/configuration/record.md

@@ -95,6 +95,29 @@ record:
 
 Continuous recording supports different retention modes [which are described below](#what-do-the-different-retain-modes-mean)
 
+### Time-Window Based Retention
+
+Recordings can be filtered to only retain footage from specific time windows after an initial period.
+
+```yaml
+record:
+  enabled: True
+  motion:
+    days: 14
+    always_retain: 48
+    hours:
+      - "mon-fri 07:00-23:00"
+      - "sat-sun 10:00-18:00"
+```
+
+Supported formats for `hours`:
+- `"07:00-23:00"` - all days
+- `"mon-fri 07:00-18:00"` - day range
+- `"sat 10:00-16:00"` - single day
+- `"22:00-06:00"` - overnight
+
+Alerts and detections are always retained regardless of time windows.
+
 ### Object Recording
 
 The number of days to record review items can be specified for review items classified as alerts as well as tracked objects.
@@ -116,7 +139,9 @@ This configuration will retain recording segments that overlap with alerts and d
 
 ## Can I have "continuous" recordings, but only at certain times?
 
-Using Frigate UI, Home Assistant, or MQTT, cameras can be automated to only record in certain situations or at certain times.
+Yes! You can use time-window based retention to keep recordings only from specific hours. See [Time-Window Based Retention](#time-window-based-retention) above.
+
+Alternatively, using Frigate UI, Home Assistant, or MQTT, cameras can be automated to only record in certain situations or at certain times.
 
 ## How do I export recordings?
 

docs/docs/configuration/reference.md

@@ -517,13 +517,31 @@ record:
     # Optional: Number of days to retain recordings regardless of tracked objects or motion (default: shown below)
     # NOTE: This should be set to 0 and retention should be defined in alerts and detections section below
     #       if you only want to retain recordings of alerts and detections.
+    #       Set to null for unlimited retention.
     days: 0
+    # Optional: Time windows to retain recordings (default: not set, keep all times)
+    # After always_retain period, only recordings within these windows are kept.
+    # Format: "HH:MM-HH:MM" or "mon-fri HH:MM-HH:MM" or "sat HH:MM-HH:MM"
+    hours:
+      - "mon-fri 07:00-23:00"
+      - "sat-sun 10:00-18:00"
+    # Optional: Hours to retain all recordings before applying time window filter (default: shown below)
+    always_retain: 24
   # Optional: Motion retention settings
   motion:
     # Optional: Number of days to retain recordings regardless of tracked objects (default: shown below)
     # NOTE: This should be set to 0 and retention should be defined in alerts and detections section below
     #       if you only want to retain recordings of alerts and detections.
+    #       Set to null for unlimited retention.
     days: 0
+    # Optional: Time windows to retain recordings (default: not set, keep all times)
+    # After always_retain period, only recordings within these windows are kept.
+    # Format: "HH:MM-HH:MM" or "mon-fri HH:MM-HH:MM" or "sat HH:MM-HH:MM"
+    hours:
+      - "mon-fri 07:00-23:00"
+      - "sat-sun 10:00-18:00"
+    # Optional: Hours to retain all recordings before applying time window filter (default: shown below)
+    always_retain: 24
   # Optional: Recording Export Settings
   export:
     # Optional: Timelapse Output Args (default: shown below).