docs: remove resolved plan for data-fix characterization tests

plans/008-add-data-fix-runner-characterization-tests.md

@@ -1,34 +0,0 @@
----
-finding: "Add data-fix runner characterization tests"
-catalog: "Tests"
-impact: "Startup data repairs can drift or fail partway without fast regression coverage."
-base_commit: "0d31d46"
----
-
-## Effort
-
-S - seed in-memory SQLite rows and assert before/after behavior.
-
-## Risk
-
-LOW - tests should use existing migration helpers and avoid production data.
-
-## Confidence
-
-HIGH - the runner and registered fixes currently lack direct characterization tests.
-
-## Evidence
-
-- `internal/database/fixes.go:33-50` runs each unapplied registered fix and records it only after success.
-- `internal/database/fixes/20260526_episode_availability_backfill_next_refresh_at.go:12-24` mutates cached episode availability rows at startup.
-- `internal/database/database_test.go:12-72` covers migrations and cache cleanup, but not `RunDataFixes` or registered fix effects.
-
-## Resolution Approach
-
-Add tests in `internal/database` or `internal/database/fixes` that use an in-memory SQLite database and existing migration helpers. Cover runner behavior and at least each registered fix’s observable effect.
-
-Runner tests should assert that unapplied fixes run, applied fix IDs are skipped, successful fixes are recorded in `data_fixes`, and failed fixes do not get marked applied. Individual fix tests should seed the minimum relevant rows, run the fix, and assert the changed fields and idempotency.
-
-If a registered fix depends on external services or slow behavior, isolate it behind existing dependency seams or test the row-selection/mutation behavior directly. Do not introduce network calls into these tests.
-
-Verify with `go test ./internal/database ./internal/database/fixes ./...`.