Fix SQL dump table identifier escaping

[swhan0329]

/claim #59

Summary

• quote sqlite_master name lookups so table names containing single quotes do not break schema discovery
• quote table identifiers for dump SELECTs and generated INSERT statements when names contain spaces/quotes or common SQLite keywords
• add regression coverage for a table name that needs both SQL string escaping and identifier quoting

This keeps the change scoped to SQL dump correctness and does not touch the broader streaming/R2 export paths.

Verification

• pnpm exec vitest run src/export/dump.test.ts
• pnpm exec prettier --check src/export/dump.ts src/export/dump.test.ts
• git diff --check
• pnpm run build

Demo

• The new regression test exercises a table named kid's profiles and verifies the escaped schema lookup, quoted SELECT, and quoted INSERT dump output.

[swhan0329]

Fresh local verification because this PR does not have GitHub checks attached:

• pnpm exec vitest run src/export/dump.test.ts -> 1 file / 6 tests passed
• pnpm exec prettier --check src/export/dump.ts src/export/dump.test.ts -> passed
• pnpm run build -> passed
• git diff --check -> passed

The change remains scoped to SQL dump correctness for table names that need SQLite string escaping and identifier quoting.