refactor: remove all biome dependencies (#677)

## Summary

Removes all `biome_*` crate dependencies from the workspace.

### `biome_string_case` → `convert_case`

Drop-in replacement. `convert_case` was already a workspace dependency.

### `biome_js_factory`, `biome_js_formatter`, `biome_js_syntax`,
`biome_rowan` → string-based TS codegen

The TS codegen only produces interfaces, type aliases, and one factory
function. Building a full JS AST for that was overkill. Raw string
templates do the same job with zero new dependencies.

### `biome_deserialize`, `biome_deserialize_macros` →
`pgls_configuration_macros` + inline `Merge`/`StringSet`

- New proc-macro crate `pgls_configuration_macros` with `Merge` and
`Partial` derives (vendored from biome, ~250 lines total, pointed at
`pgls_configuration::Merge` instead of `biome_deserialize::Merge`).
- `Merge` trait (49 lines, zero deps) and `StringSet` wrapper (86 lines,
only `indexmap`) inlined into `pgls_configuration::utils`.
- `Deserializable` derive and `DeserializableValidator` dropped entirely
— never called at runtime.

---------

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

Author: psteinroe

.github/workflows/pull_request.yml

@@ -315,6 +315,8 @@ jobs:
       - name: Install toolchain
         uses: moonrepo/setup-rust@v1
         with:
+          components: rustfmt
+          bins: taplo-cli
           cache-base: main
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
@@ -327,18 +329,16 @@ jobs:
         run: command -v tree-sitter || cargo install tree-sitter-cli
       - name: Ensure RustFMT on nightly toolchain
         run: rustup component add rustfmt --toolchain nightly
-      - name: echo toolchain
-        run: rustup show
-      - name: Run the analyser codegen
-        run: cargo run -p xtask_codegen -- analyser
-      - name: Run the configuration codegen
-        run: cargo run -p xtask_codegen -- configuration
-      - name: Run the bindings codegen
-        run: cargo run -p xtask_codegen -- bindings
-      - name: Run the splinter codegen
-        run: cargo run -p xtask_codegen -- splinter
-      - name: Run the docs codegen
-        run: cargo run -p docs_codegen
+      - name: Setup Bun
+        uses: oven-sh/setup-bun@v2
+        with:
+          bun-version: "1.2.17"
+      - name: Install JS dependencies
+        run: bun install
+      - name: Setup Just
+        uses: extractions/setup-just@v3
+      - name: Run codegen
+        run: just gen-lint
       - name: Check for git diff -- run "just ready" if you see an error
         run: |
           if [[ $(git status --porcelain) ]]; then