Add backup/restore, daily auto-backup and history CSV/JSON export (Phase E3)

- create_backup writes a zip (manifest with sha256 per file, a VACUUM INTO database snapshot, assets, archive, fonts) atomically. restore_backup validates the manifest, rejects tampered files, path traversal, symlinks and newer schemas, checks the staged DB with integrity_check, then stages a pending restore. The swap runs on the next start before the database opens, moves the current data to backups/pre-restore-<ts>/ and rolls back on any failure.
- Daily automatic backup (migration M9 auto_backup, default on) keeps the newest 14 and never blocks startup.
- Settings Data tab: back up now, restore with confirmation and restart, auto-backup toggle, last backup time.
- History exports the filtered rows as CSV (UTF-8 BOM, CRLF, formula-injection guard) or JSON (voiced.history.v1) with CA-friendly tax columns from a new list_invoice_ledger command.
- Rust round-trip, rejection, swap-rollback and retention tests; vitest for the export and backup helpers.

Adds the zip 8.6.0 and typed-path 0.12.3 crates (pure Rust); package builds must vendor them. PDF output and fingerprint goldens are unchanged. The new UI has not been run in a webview yet.

src-tauri/Cargo.lock

@@ -4188,6 +4188,12 @@ version = "0.2.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e421abadd41a4225275504ea4d6566923418b7f05506fbc9c0fe86ba7396114b"
 
+[[package]]
+name = "typed-path"
+version = "0.12.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8e28f89b80c87b8fb0cf04ab448d5dd0dd0ade2f8891bae878de66a75a28600e"
+
 [[package]]
 name = "typeid"
 version = "1.0.3"
@@ -4307,6 +4313,7 @@ dependencies = [
  "tempfile",
  "thiserror 2.0.21",
  "uuid",
+ "zip",
 ]
 
 [[package]]
@@ -5182,6 +5189,19 @@ dependencies = [
  "syn 3.0.6",
 ]
 
+[[package]]
+name = "zip"
+version = "8.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2d04a6b5381502aa6087c94c669499eb1602eb9c5e8198e534de571f7154809b"
+dependencies = [
+ "crc32fast",
+ "flate2",
+ "indexmap 2.14.2",
+ "memchr",
+ "typed-path",
+]
+
 [[package]]
 name = "zlib-rs"
 version = "0.6.8"