claude: Fix extension-build import-map to work in both dev and dist modes

Problem: import-map.json pointed to ./quarto-types.d.ts which doesn't
exist in dev mode (src/resources/extension-build/).

Solution: Follow Lua filter transformation pattern:
- Source file in src/resources/ uses dev-mode path
- Transform during packaging for distribution

Changes:
- import-map.json now points to ../../../packages/quarto-types/dist/index.d.ts
  (works in dev mode from src/resources/extension-build/)
- Added updateImportMap() function in prepare-dist.ts that:
  - Runs after supportingFiles() copies all resources
  - Transforms @quarto/types path to ./quarto-types.d.ts for distribution
  - Updates all Deno std versions from src/import_map.json
  - Loops over all imports dynamically (not hardcoded list)
- Updated README.md to document dev vs distribution behavior

Result: Default config now works in dev mode without committing generated
artifacts to src/resources/.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: gordonwoodhull

package/src/common/prepare-dist.ts

@@ -118,6 +118,11 @@ export async function prepareDist(
   supportingFiles(config);
   info("");
 
+  // Update extension-build import map for distribution
+  info("Updating extension-build import map");
+  updateImportMap(config);
+  info("");
+
   // Create the deno bundle
   // const input = join(config.directoryInfo.src, "quarto.ts");
   const output = join(config.directoryInfo.pkgWorking.bin, "quarto.js");
@@ -172,8 +177,8 @@ export async function prepareDist(
   );
 
   // Copy quarto-types to extension-build directory
-  // Note: src/resources/extension-build/ already has deno.json and import-map.json
-  // which are copied automatically by supportingFiles()
+  // Note: deno.json and import-map.json are copied by supportingFiles() and
+  // import-map.json is then updated by updateImportMap() for distribution
   info("Copying quarto-types.d.ts to extension-build directory");
   const extensionBuildDir = join(
     config.directoryInfo.pkgWorking.share,
@@ -231,6 +236,49 @@ function supportingFiles(config: Configuration) {
   pathsToClean.forEach((path) => Deno.removeSync(path, { recursive: true }));
 }
 
+function updateImportMap(config: Configuration) {
+  // Read the import map that was copied from src/resources/extension-build/
+  const importMapPath = join(
+    config.directoryInfo.pkgWorking.share,
+    "extension-build",
+    "import-map.json",
+  );
+  const importMapContent = JSON.parse(Deno.readTextFileSync(importMapPath));
+
+  // Read the source import map to get current Deno std versions
+  const sourceImportMapPath = join(config.directoryInfo.src, "import_map.json");
+  const sourceImportMap = JSON.parse(Deno.readTextFileSync(sourceImportMapPath));
+  const sourceImports = sourceImportMap.imports as Record<string, string>;
+
+  // Update the import map for distribution:
+  // 1. Change @quarto/types path from dev (../../../packages/...) to dist (./quarto-types.d.ts)
+  // 2. Update all other imports (Deno std versions) from source import map
+  const updatedImports: Record<string, string> = {
+    "@quarto/types": "./quarto-types.d.ts",
+  };
+
+  // Copy all other imports from source, updating versions
+  for (const key in importMapContent.imports) {
+    if (key !== "@quarto/types") {
+      const sourceValue = sourceImports[key];
+      if (!sourceValue) {
+        throw new Error(
+          `Import map key "${key}" not found in source import_map.json`,
+        );
+      }
+      updatedImports[key] = sourceValue;
+    }
+  }
+
+  importMapContent.imports = updatedImports;
+
+  // Write back the updated import map
+  Deno.writeTextFileSync(
+    importMapPath,
+    JSON.stringify(importMapContent, null, 2) + "\n",
+  );
+}
+
 interface Filter {
   // The name of the filter (the LUA file and perhaps the directory)
   name: string;

src/resources/extension-build/README.md

@@ -6,19 +6,22 @@ This directory contains default configuration files for TypeScript execution eng
 
 - **deno.json** - Default TypeScript compiler configuration
 - **import-map.json** - Import mappings for @quarto/types and Deno standard library
-- **quarto-types.d.ts** - Type definitions for Quarto API (copied from packages/quarto-types/dist/ during build)
+- **quarto-types.d.ts** - Type definitions (copied from packages/quarto-types/dist/ during packaging)
 
 ## Usage
 
 These files are used by `quarto dev-call build-ts-extension` when a user project doesn't have its own `deno.json`.
 
-In dev mode: accessed via `resourcePath("extension-build/")`
-In distribution: copied to `share/extension-build/` during packaging
+**Dev mode:** Accessed via `resourcePath("extension-build/")`
+- `import-map.json` points to `../../../packages/quarto-types/dist/index.d.ts`
+- This relative path works from `src/resources/extension-build/`
 
-## Updating Versions
+**Distribution mode:** Copied to `share/extension-build/` during packaging
+- `import-map.json` is transformed by `updateImportMap()` in prepare-dist.ts
+- `@quarto/types` path changed to `./quarto-types.d.ts`
+- Deno std versions updated from `src/import_map.json`
 
-When updating Deno standard library versions:
-1. Update `src/import_map.json` (main Quarto CLI import map)
-2. Update `import-map.json` in this directory to match
+## Updating Versions
 
-The versions should stay in sync with Quarto CLI's dependencies.
+Deno std library versions are automatically synced from `src/import_map.json` during packaging.
+No manual updates needed to this directory's import-map.json versions.

src/resources/extension-build/import-map.json

@@ -1,6 +1,6 @@
 {
   "imports": {
-    "@quarto/types": "./quarto-types.d.ts",
+    "@quarto/types": "../../../packages/quarto-types/dist/index.d.ts",
     "path": "jsr:@std/path@1.0.8",
     "path/posix": "jsr:@std/path@1.0.8/posix",
     "log": "jsr:/@std/log@0.224.0",