fix(ts-sdk): resolve sqlite db paths in OSS mode

[mudrii]

Description

Fixes two OSS SQLite path bugs in the TypeScript SDK:

• propagate top-level historyDbPath into historyStore.config.historyDbPath when the history provider is sqlite
• make the memory vector store SQLite path configurable via vectorStore.config.dbPath
• default the vector store database to ~/.mem0/vector_store.db instead of resolving from process.cwd()
• create parent directories for file-backed SQLite databases before opening them
• add regression tests covering both fixes, including a non-writable CWD case

Fixes #4290

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Refactor (does not change functionality, e.g. code style improvements, linting)
• Documentation update

How Has This Been Tested?

• Unit Test
• Test Script (please provide)

Commands run locally:

cd mem0-ts
npx prettier --check src/oss/src/config/manager.ts src/oss/src/storage/SQLiteManager.ts src/oss/src/tests/sqlite-path-resolution.test.ts src/oss/src/types/index.ts src/oss/src/utils/sqlite.ts src/oss/src/vector_stores/memory.ts
npm test -- --runInBand src/oss/src/tests/better-sqlite3-migration.test.ts src/oss/src/tests/sqlite-path-resolution.test.ts
npm run build

Additional note: npm test -- --runInBand for the entire mem0-ts package still hits pre-existing failures in unrelated integration-style tests (src/client/tests/memoryClient.test.ts, src/oss/tests/memory.test.ts) that require external services / outdated call signatures. This PR does not modify those areas.

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules
• I have checked my code and corrected any misspellings

Maintainer Checklist

• closes [Bug] historyDbPath ignored in open-source mode — SQLite always uses relative "memory.db" + vector_store.db uses process.cwd() #4290
• Made sure Checks passed

[CLAassistant]

All committers have signed the CLA.

[alvinttang]

The ensureSQLiteDirectory utility is clean and the :memory: guard is correct. One subtle issue: dbPath.startsWith('file:') skips directory creation for all file-URI paths, including file:/abs/path/to/db.sqlite which is a real on-disk path — if its parent directory doesn't exist the open will fail. Consider only skipping when the path is file::memory: or contains ?mode=memory. Additionally, the top-level historyDbPath propagation in manager.ts only injects into historyStore.config when the provider is SQLite, which is correct, but if userConfig.historyStore is provided with a non-SQLite provider, the top-level historyDbPath is silently dropped — worth at minimum a warning log.