feat(lsp): add config-driven LSP support (Roblox Luau via luau-lsp)

Add Language Server Protocol integration modeled on opencode's, wired for
this codebase's plain-TypeScript tool/agent architecture.

Core (@dispatch/core):
- lsp/client.ts: LSP/JSON-RPC client over stdio (vscode-jsonrpc) with the
  initialize handshake, didOpen/didChange sync, push + pull diagnostics
  (textDocument/diagnostic, workspace/diagnostic), and a generic request()
  passthrough for hover/definition/references/documentSymbol.
- lsp/server.ts: resolves dispatch.toml [lsp] entries into spawn specs.
  Config-driven only — no builtin registry, no auto-download.
- lsp/manager.ts: process-wide LspManager owning client lifecycles, keyed
  by root+serverID, lazy spawn + reuse + graceful shutdown.
- lsp/language.ts: extension->languageId map incl. .luau -> "luau".
- lsp/diagnostic.ts: error-only <diagnostics> block formatting (1-based).
- tools/lsp.ts: on-demand 'lsp' tool (1-based coords -> 0-based wire).
- write-file.ts: optional onAfterWrite hook for diagnostics-on-write.
- config schema: validate [lsp] block; DispatchConfig.lsp + LspServerConfig.

API (@dispatch/api):
- AgentManager owns one LspManager; per-working-directory server cache
  cleared on config reload; diagnostics appended to write_file results;
  'lsp' tool gated by new perm_lsp setting; shutdownAll on destroy().

Config:
- dispatch.toml: documented, commented [lsp.luau-lsp] Roblox example.

Tests: fake-lsp-server fixture + client/manager/server/diagnostic/schema/
tool/write-hook suites, plus an opt-in real-binary luau-lsp smoke test
(auto-skipped when luau-lsp is absent). 652 pass; biome + 3 typechecks green.

1 files changed, 6 insertions, 0 deletions

diff --git a/bun.lock b/bun.lock
index b6c5e6a..b92950e 100644
--- a/bun.lock
+++ b/bun.lock
@@ -31,6 +31,8 @@
         "chokidar": "^5.0.0",
         "smol-toml": "^1.6.1",
         "tree-sitter-bash": "^0.25.1",
+        "vscode-jsonrpc": "8.2.1",
+        "vscode-languageserver-types": "3.17.5",
         "web-tree-sitter": "^0.26.8",
         "zod": "^3.23.0",
         "zod-to-json-schema": "^3.25.2",
@@ -907,6 +909,10 @@
 
     "vitest": ["[email protected]", "", { "dependencies": { "@types/chai": "^5.2.2", "@vitest/expect": "3.2.4", "@vitest/mocker": "3.2.4", "@vitest/pretty-format": "^3.2.4", "@vitest/runner": "3.2.4", "@vitest/snapshot": "3.2.4", "@vitest/spy": "3.2.4", "@vitest/utils": "3.2.4", "chai": "^5.2.0", "debug": "^4.4.1", "expect-type": "^1.2.1", "magic-string": "^0.30.17", "pathe": "^2.0.3", "picomatch": "^4.0.2", "std-env": "^3.9.0", "tinybench": "^2.9.0", "tinyexec": "^0.3.2", "tinyglobby": "^0.2.14", "tinypool": "^1.1.1", "tinyrainbow": "^2.0.0", "vite": "^5.0.0 || ^6.0.0 || ^7.0.0-0", "vite-node": "3.2.4", "why-is-node-running": "^2.3.0" }, "peerDependencies": { "@edge-runtime/vm": "*", "@types/debug": "^4.1.12", "@types/node": "^18.0.0 || ^20.0.0 || >=22.0.0", "@vitest/browser": "3.2.4", "@vitest/ui": "3.2.4", "happy-dom": "*", "jsdom": "*" }, "optionalPeers": ["@edge-runtime/vm", "@types/debug", "@types/node", "@vitest/browser", "@vitest/ui", "happy-dom", "jsdom"], "bin": { "vitest": "vitest.mjs" } }, "sha512-LUCP5ev3GURDysTWiP47wRRUpLKMOfPh+yKTx3kVIEiu5KOMeqzpnYNsKyOoVrULivR8tLcks4+lga33Whn90A=="],
 
+    "vscode-jsonrpc": ["[email protected]", "", {}, "sha512-kdjOSJ2lLIn7r1rtrMbbNCHjyMPfRnowdKjBQ+mGq6NAW5QY2bEZC/khaC5OR8svbbjvLEaIXkOq45e2X9BIbQ=="],
+
+    "vscode-languageserver-types": ["[email protected]", "", {}, "sha512-Ld1VelNuX9pdF39h2Hgaeb5hEZM2Z3jUrrMgWQAu82jMtZp7p3vJT3BzToKtZI7NgQssZje5o0zryOrhQvzQAg=="],
+
     "web-tree-sitter": ["[email protected]", "", {}, "sha512-4sUwi7ZyOrIk5KLgYLkc2A/F0LFMQnBhfb+2Cdl7ik4ePJ6JD+fk4ofI2sA5eGawBKBaK4Vntt7Ww5KcEsay4A=="],
 
     "which": ["[email protected]", "", { "dependencies": { "isexe": "^3.1.1" }, "bin": { "node-which": "bin/which.js" } }, "sha512-JEdGzHwwkrbWoGOlIHqQ5gtprKGOenpDHpxE9zVR1bWbOtYRyPPHMe9FaP6x61CmNaTThSkb0DAJte5jD+DmzQ=="],