0.7.2

🐛 Daily Notes: empty marker pair now gets filled on backfill

Fixes a bug surfaced by users with a custom Daily Note template that pre-injects the trakt markers as an empty pair %% trakt:daily:start %% / %% trakt:daily:end %%. Before 0.7.2, the past-day branch of processDate treated any valid marker pair — even empty — as "already filled" and skipped writing. Manual backfill silently did nothing for those days.

What changed

Added isMarkerRegionEmpty to distinguish:

• Empty pair (template-injected, just newlines / whitespace between markers) → fill in place via replaceMarkerBlock
• Pair with real content → preserve (existing safety, unchanged)

The original safety contract (spec 0006) is unchanged: regions with any non-whitespace content between markers continue to be skipped on past-day catch-up + manual backfill.

Tests

• 8 new smoke test cases covering empty / whitespace-only / mixed-content marker regions
• All 361 existing tests pass

Affected behaviour

Scenario	Before 0.7.2	After 0.7.2
Daily Note template injects empty markers	Backfill no-op (bug)	Backfill fills the region ✓
Past day with hand-written events between markers	Skipped	Skipped (unchanged)
Past day with no markers at all	Append fresh region to end of file	Same