refactor: eliminate dead and unused data files (~1 MB removed)

[shivv23]

Eliminates dead and unused data files, removing 11,378 lines (~1,058 KB) from the source tree.

Changes

Deleted src/app-data-new.ts (9,426 lines, 824 KB)

• Alternative data file for "Inventory Tracker for FVM Warehouse" — never imported by any source file
• Structurally identical to app-data.ts with different branding; clearly an abandoned variant

Removed DATA["ledger"] from src/app-data.ts (1,952 lines, ~234 KB)

• The ledger key contained a full set of SocialCalc spreadsheet templates (invoice layouts) that were loaded into memory at module import time but never accessed by any consumer
• All five consumers (Home.tsx, Files.tsx, Dashboard.tsx, NewFile.tsx, Menu.tsx) only read DATA["home"] — the ledger key was dead weight

Impact

• src/app-data.ts: 3,908 lines reduced to 1,956 lines (50% reduction)
• src/app-data-new.ts: fully removed from the codebase
• Total: 11,378 lines deleted, ~1,058 KB of dead/unused data eliminated

Note

npx tsc --noEmit shows a pre-existing error for @meshkit/ionic module resolution (the local file:../Ionic-meshkit-release dependency does not exist on this machine). This is unrelated to this PR and is addressed in PR #1 which adds a type declaration stub.