fix(todo): make sticky-dismissed suggestions immune to feedback-log truncation

[Gagancreates]

Summary

Fixes a bug where the Home suggestion tray could re-show a suggestion the user had already declined. The sticky-dismissed verdict was previously derived from the bounded 200-entry planner feedback ledger, so enough unrelated signals could truncate the original dismissal and allow the suggestion to be proposed again.

This change adds a new uncapped todo/sticky_dismissed.json store separate from the bounded feedback ledger. Dismissed and taught signals upsert into that sticky store, while later ran or kept signals remove the key to preserve the existing override semantics. The bounded ledger remains in place for recent outcome examples.

It also awaits planner signal persistence at the accept, decline, dismiss, teach, and run call sites while still swallowing signal-recording failures, closing the race where a planner run could read sticky dismissals before a just-recorded user action had reached disk.

Fixes #830

Testing

• Added unit tests in apps/x/packages/core/src/todo/planner-memory.test.ts covering sticky dismissal persistence past feedback-log truncation, taught signals, and ran/kept overrides.
• npm test -- src/todo/fileops.test.ts src/todo/planner-memory.test.ts: 2 files passed, 11 tests passed.
• npm test in apps/x/packages/core: 54 files passed, 583 tests passed.
• npm run typecheck in apps/x/packages/core: passed.
• npm run build in apps/x/packages/core: passed.
• npm run build in apps/x/apps/main: passed.