[codex] Add Doltlite storage strategy

[JanJakes]

Summary

Adds a new doltlite storage strategy that uses Doltlite as the branchable SQLite backing store for both WordPress database tables and BranchFS-managed files.

This includes runtime routing/bootstrap support, Doltlite control commands, BranchFS branch checkout integration, SQLite Database Integration patches needed for Doltlite branch checkout, static PHP build integration for Doltlite, storage-driver documentation, and performance fixes for Doltlite-backed BranchFS reads/imports.

Validation

• scripts/build-dist.sh completed and the resulting PHP reported doltlite_engine() = prolly.
• FORKPRESS_RUNTIME_BUNDLE=/dev/null cargo test -p forkpress passed: 21/21.
• cargo build -p forkpress passed.
• PHP lint passed for the Doltlite runtime/control scripts plus touched init/import scripts.
• Fresh forkpress init --strategy doltlite completed in about 9.6s after import transaction optimization.
• Main page served after init: 200 in about 0.65s.
• Branch preview served after creating a branch: 200 in about 0.65s.
• End-to-end smoke covered Doltlite branch creation/list/status, server start, and Git clone from /site.git.

Known follow-ups

This remains a draft because the Git write path still needs work before review-ready status:

• Git push / forkpress commit is wired but still needs optimization and correctness work in post-push import/commit processing.
• Push rollback for Doltlite is still stubbed pending a validated reset-to-hash path.
• CI/release validation is still needed across the supported Linux musl and macOS targets.

Manual testing

rm -rf .forkpress .fp-doltlite-clone

target/debug/forkpress init --strategy doltlite --admin-password admin
target/debug/forkpress branch create test --from main
target/debug/forkpress branch list

target/debug/forkpress server start --port 18181 --background

curl -i http://127.0.0.1:18181/
curl -i -H 'Host: test.wp.localhost:18181' http://127.0.0.1:18181/

git clone http://127.0.0.1:18181/site.git .fp-doltlite-clone

target/debug/forkpress server stop

Expected: init should complete in seconds rather than minutes, and page loads should be fast once the server is running.