feat(zed): add Zed extension wrapping sqlshield-lsp

A native Zed extension under editors/zed/. Compiles to wasm32-wasip1
via zed_extension_api 0.7.0 and registers a `sqlshield` language
server attached to SQL, Python, Rust, Go, JS/JSX, and TS/TSX buffers.

Binary discovery is layered: explicit `lsp.sqlshield.binary.path` →
`sqlshield-lsp` on PATH (the cargo install path) → a GitHub-release
download keyed by `(platform, arch)`. The release-download path is
guarded by an `sqlshield-lsp-v*` tag check so it won't grab assets
from a sibling crate's tag.

Workspace-configuration hook forwards `lsp.sqlshield.settings` to the
LSP unchanged, so the same `schema` / `dialect` knobs that already
work in VS Code work here too — server-side merging with
.sqlshield.toml is unchanged.

The crate is excluded from the main Cargo workspace because it
targets wasm32-wasip1 and pulls in zed_extension_api, which would
otherwise interfere with native cargo build/test/clippy.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: davidsmfreire

.gitignore

@@ -1,5 +1,6 @@
 .venv
 /target
+**/target/
 .vscode
 
 # Python

Cargo.toml

@@ -7,6 +7,10 @@ members = [
   "sqlshield-lsp",
   "sqlshield-py",
 ]
+# editors/zed targets wasm32-wasip1 and uses zed_extension_api; keep
+# it out of the main workspace so it doesn't interfere with normal
+# cargo build/test/clippy commands.
+exclude = ["editors/zed"]
 # Root `sqlshield-precommit` package is a pre-commit shim; exclude from
 # default builds so it doesn't clobber sqlshield-cli's `sqlshield` bin.
 default-members = [