feat: time-aware model routing for cron jobs (#317)

Route cron jobs to different models based on time of day.

- Peak hours (user active): cheaper model, user catches errors
- Off-peak hours (user absent): stronger model, errors go uncorrected

Config under smart_model_routing.cron_time_routing:
  enabled, timezone, peak_hours (start/end), peak_model, offpeak_model

Integrates into cron/scheduler.py via resolve_cron_turn_route(), which
checks time-aware routing first, then falls back to normal smart routing.

12 tests added (test_cron_time_routing.py). All 18 routing tests pass.

Closes #317

cli-config.yaml.example

@@ -87,6 +87,21 @@ model:
 #   cheap_model:
 #     provider: openrouter
 #     model: google/gemini-2.5-flash
+#   # Time-aware cron routing: pick model based on hour of day.
+#   # Peak hours = user present, cheaper model OK (they catch errors).
+#   # Off-peak = user absent, stronger model (errors go uncorrected).
+#   cron_time_routing:
+#     enabled: true
+#     timezone: "America/New_York"   # IANA timezone (default: UTC)
+#     peak_hours:
+#       start: 9   # inclusive, 0-23
+#       end: 18    # exclusive, 0-23
+#     peak_model:                      # model during peak hours (user active)
+#       provider: openrouter
+#       model: xiaomi/mimo-v2-pro
+#     offpeak_model:                   # model during off-peak (user absent)
+#       provider: openrouter
+#       model: anthropic/claude-sonnet-4
 
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