P3: depreciation straight-line by days through the final month, schedules by day (defects 22, 9, D-37)

The final month takes what the months before leave, spread over its days;
a disposed asset stops on its disposal day. A skipped month is caught up
in the month the run is made; a reversed run un-posts its month. New
schedules spread by day; equal-months schedules must start on the 1st.
Amounts round to the currency's own minor unit. Kani and Lean proofs; an
exhaustive search over runs, reversals and disposals.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01T3gXMVt7XJPi6ens1or9Dj

crates/ledger-config/tests/codec_props.rs

@@ -62,6 +62,8 @@ fn candidates() -> Vec<(&'static str, Value)> {
         ("books.close_into", json!("3000")),
         ("books.close_sweep", json!(["3100"])),
         ("books.asset_tag_prefix", json!("FL")),
+        ("books.schedule_convention", json!("monthly_even")),
+        ("books.schedule_convention", json!("daily")),
         ("policy.evidence.threshold", json!("0.00")),
         ("policy.evidence.threshold", json!("25.5")),
         ("policy.evidence.required_accounts", json!(["6200"])),