dogfood: webjs ui subcommand fails to resolve @webjsdev/ui bin (exports gate)

[vivek7405]

Problem

webjs ui <subcmd> (and npx webjsdev ui add <name>) fails to launch even when @webjsdev/ui is installed, printing the misleading @webjsdev/ui could not be resolved. Reinstall the CLI: npm install -g webjsdev. The real cause is a resolver gate, not a missing package:

• The ui dispatch in packages/cli/bin/webjs.js (the case 'ui': block, ~L499-520) resolves the bin by SUBPATH: req.resolve('@webjsdev/ui/bin/webjsui.js') (both the CLI-rooted and the cwd-fallback attempt).
• @webjsdev/ui's package.json exports map lists only ., ./registry/schema, ./registry/extract, ./utils. With an exports field present, Node BLOCKS every unlisted subpath, so require.resolve('@webjsdev/ui/bin/webjsui.js') throws ERR_PACKAGE_PATH_NOT_EXPORTED even though packages/ui/bin/webjsui.js physically exists (verified).
• Both attempts therefore throw, and the catch prints the misleading reinstall message. Running the bin file directly works, which is why it looks like a phantom resolution failure.

Found dogfooding: an agent building a real app could not run npx webjsdev ui add tabs, assumed the kit was unavailable, and hand-rolled the UI (tabs/buttons/inputs) instead, which then needed manual fixes (e.g. cursor-pointer) the official components would have carried. So this bug is a direct cause of agents hand-writing UI instead of using the kit (compounding #1070).

Design / approach

The CLI already has the exact fix for an exports-blocked bin: lib/resolve-bin.js resolveBin(cwd, pkgName, binName) (#570), which resolves the package's . export (always exported), walks to the package root, and reads the bin map. webjs db and webjs test --browser already use it; the ui dispatch was simply missed and still uses the raw subpath resolve. Switch the ui dispatch to resolveBin, keeping the CLI-root-first (hard-dep) then cwd-fallback order, and spawn with process.execPath (matching the sibling db/test paths, so it works under Bun / a Node-less image) instead of the literal 'node'.

Alternative considered and rejected: add "./bin/webjsui.js" to @webjsdev/ui's exports. That would also fix it, but it is a second package's change and leaves the CLI resolving bins two different ways; using the existing resolveBin is the single, consistent, version-robust fix (works regardless of the ui package's exports).

Implementation notes (for the implementing agent)

• Where to edit: packages/cli/bin/webjs.js, the case 'ui': block (~L499-523). Replace both req.resolve('@webjsdev/ui/bin/webjsui.js') attempts with resolveBin(join(__dirname, '..'), '@webjsdev/ui', 'webjsui') (hard-dep, the CLI's own node_modules) then a resolveBin(process.cwd(), '@webjsdev/ui', 'webjsui') fallback (user installed it directly). Keep the same clear error + exit on total failure. resolveBin, __dirname, join, dirname, fileURLToPath are ALREADY imported at the top of the file, so no new imports. Drop the now-unused local createRequire in that block. Change spawn('node', ...) to spawn(process.execPath, ...).
• Landmines: resolveBin(cwd, ...) roots resolution at join(cwd, 'package.json'), so pass the CLI package ROOT (join(__dirname, '..'), which is packages/cli) for the hard-dep path, NOT __dirname (the bin/ dir). In the monorepo @webjsdev/ui's . export is ./src/index.js; in a published install it may differ, but resolveBin walks to the package root either way, so it is layout-robust. Do NOT re-add a catch-all subpath resolve.
• Invariants: CLI package invariant 1 (exactly the templates/flags surface, unchanged here); this is a resolution fix, no new command. Respect the prose-punctuation invariant (release: bump core/server/cli versions, honest engines fields #11) in any new comment.
• Tests: extend packages/cli/test/resolve-bin/resolve-bin.test.mjs with a case asserting resolveBin(<cli root or repo root>, '@webjsdev/ui', 'webjsui') returns the real bin/webjsui.js path (and existsSync), PLUS a counterfactual that createRequire(...).resolve('@webjsdev/ui/bin/webjsui.js') THROWS ERR_PACKAGE_PATH_NOT_EXPORTED (proving the exports gate the fix bypasses). Optionally a test/cli/* spawn-level assertion that webjs ui list exits 0.
• Verify: run webjs ui list (or node packages/cli/bin/webjs.js ui list) and confirm it launches the kit instead of the reinstall error.
• Docs: none required (bugfix, no surface change). Mention in the cli changelog via the PR title (fix:).

Acceptance criteria

• webjs ui list / npx webjsdev ui add <name> launches the kit when @webjsdev/ui is installed, no false "could not be resolved" error
• The ui dispatch resolves via resolveBin, consistent with db / test --browser, and spawns with process.execPath
• Test asserts resolveBin resolves the webjsui bin despite the exports gate, with a counterfactual that the raw subpath resolve throws ERR_PACKAGE_PATH_NOT_EXPORTED
• The genuine not-installed case still prints the clear error and exits non-zero