feat(config): merge home-directory global dispatch.toml under project config

Load an optional global config at ~/.config/dispatch/dispatch.toml
(override via DISPATCH_GLOBAL_CONFIG) and deep-merge it underneath every
project/working-directory dispatch.toml, so machine-wide settings — most
notably globally available LSP servers — work in any repo without per-repo
config. Local always wins on conflicts.

- loader: add getGlobalConfigPath(), loadGlobalConfig(), mergeConfigs();
  loadConfig(dir) now loads+merges global. [lsp] and [[keys]] merge by id;
  [permissions] merge per-group with global patterns emitted first so local
  rules win at evaluation time (findLast). A malformed global config is
  downgraded to empty rather than breaking every repo.
- watcher: watch BOTH global and local dispatch.toml so hot-reload re-merges
  on either change (dedupes when paths coincide).
- export new loader fns from config/index and core index.
- types/agent-manager: doc updates reflecting merged LSP resolution.
- dispatch.toml: document global-default merge behavior; activate biome and
  typescript-language-server LSP entries.
- tests: merge precedence, lsp/keys merge-by-id, permissions merge,
  filesystem integration, malformed-global resilience; isolate global path
  in existing loader tests.

1 files changed, 16 insertions, 4 deletions

diff --git a/packages/core/src/config/watcher.ts b/packages/core/src/config/watcher.ts
index 70821ed..9414ef6 100644
--- a/packages/core/src/config/watcher.ts
+++ b/packages/core/src/config/watcher.ts
@@ -1,16 +1,28 @@
 import { join } from "node:path";
 import { watch } from "chokidar";
 import type { DispatchConfig } from "../types/index.js";
-import { loadConfig } from "./loader.js";
+import { getGlobalConfigPath, loadConfig } from "./loader.js";
 
+/**
+ * Watch BOTH the HOME-directory global `dispatch.toml` and the project/working-
+ * directory `dispatch.toml`. Either file changing triggers a reload that
+ * re-merges global + local (via {@link loadConfig}), so hot-reload works for
+ * global defaults and per-project overrides alike.
+ *
+ * When the global and local paths coincide (e.g. the working directory IS
+ * `~/.config/dispatch`, or `DISPATCH_GLOBAL_CONFIG` points at the local file)
+ * the duplicate is collapsed so chokidar only watches it once.
+ */
 export function createConfigWatcher(
 	dir: string,
 	onChange: (config: DispatchConfig) => void,
 ): { close(): void } {
-	const tomlPath = join(dir, "dispatch.toml");
+	const localPath = join(dir, "dispatch.toml");
+	const globalPath = getGlobalConfigPath();
+	const paths = globalPath === localPath ? [localPath] : [globalPath, localPath];
 	let debounceTimer: ReturnType<typeof setTimeout> | null = null;
 
-	const watcher = watch(tomlPath, {
+	const watcher = watch(paths, {
 		ignoreInitial: true,
 		persistent: false,
 	});
@@ -21,7 +33,7 @@ export function createConfigWatcher(
 		}
 		debounceTimer = setTimeout(() => {
 			debounceTimer = null;
-			console.log(`dispatch: reloading config from ${tomlPath}`);
+			console.log(`dispatch: reloading config (global + ${localPath})`);
 			try {
 				const config = loadConfig(dir);
 				onChange(config);