Architecture: cora debt reads from file snapshots, not cora.db (SoT gap) #403

Problem

cora debt reads from .cora/history/*.json file snapshots while cora findings reads from cora.db. This creates a data inconsistency:

The DB is supposed to be the Single Source of Truth (SoT) since v0.8.4.

Expected

cora debt should read from cora.db (reviews + findings tables) instead of file-based snapshots. File snapshots should be deprecated or synced.

Impact

• cora debt shows stale/phantom data from old reviews that pre-date DB persistence
• Users see conflicting numbers between cora debt and cora findings stats
• File-based snapshots are not portable, not queryable, and prone to corruption

Proposed Fix

1. Migrate debt_tracker to read from cora.db reviews/findings tables
2. Optionally keep file snapshots as a backup/fallback
3. Consider a migration tool to backfill DB from existing snapshot files

Related

• Save review findings to cora.db (v5 tables) #397, Save scan findings to cora.db - fix scan history gap #398: DB persistence was added in v0.8.4
• cora findings CLI - list, dismiss, reopen, stats #400: cora findings CLI added