convert lingua repo from single crate to workspace repo

[knjiang]

Convert lingua from single crate to workspace repo for introducing more crates in the future, namely braintrust-llm-router

Testing:

verified tests passing in main repo.

1. Core Rust Build System

Command	Result
cargo check --all-features	PASS
cargo build	PASS
cargo test	105 tests passed
cargo fmt --all -- --check	PASS
cargo clippy --all-targets --all-features -- -D warnings	PASS

2. Makefile Targets

Target	Result
make help	PASS
make check	PASS
make generate-types	PASS (20 tests)
make install-wasm-tools	PASS
make lingua-wasm	PASS (after fix)
make typescript	PASS
make python	PASS (after fix)
make test-rust	PASS
make test-typescript	PASS (69 tests)
make test-python	PASS (20 tests)
make test-typescript-integration	FAIL (pre-existing: missing script)

3. Scripts

Script	Result
./scripts/install-hooks.sh	PASS
./scripts/setup.sh	PASS

4. Provider Type Generation Pipelines

Pipeline	Result
./pipelines/generate-provider-types.sh openai	PASS (after fix)
./pipelines/generate-provider-types.sh anthropic	PASS
./pipelines/generate-provider-types.sh google	PASS

5. GitHub CI Workflow Commands (Local Validation)

Step	Result
cargo fmt --all -- --check	PASS
cargo clippy --all-targets --all-features -- -D warnings	PASS
RUSTFLAGS="-D warnings" cargo build --verbose	PASS
RUSTFLAGS="-D warnings" cargo test --verbose	PASS
TypeScript generation up-to-date check	PASS

6. Workspace Structure

Test	Result
cargo check -p lingua (individual crate)	PASS
cargo check -p generate-types (individual crate)	PASS
cargo run --bin generate-types (binary)	PASS
pnpm workspace packages accessible	PASS

[knjiang]

• convert lingua repo from single crate to workspace repo #48 👈 (View in Graphite)
• main

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[knjiang]

this flat hierarchy pattern was recommended here -> https://matklad.github.io/2021/08/22/large-rust-workspaces.html