fix: root Claude Code lua_ls at ~/.config/nvim

- lua-lsp rooted lua_ls at $HOME: ignored .luarc.json, flooded
  'Undefined global vim', no IntelliSense on the nvim config.
- New local marketplace/plugin lua-lsp-local@local-lsp: .lsp.json sets
  workspaceFolder=~/.config/nvim, Neovim runtime as workspace.library,
  diagnostics.libraryFiles=Disable.
- Disable official lua-lsp (enabledPlugins) so one server owns .lua.
- Verified by probe: rootUri now file:///home/tvanbesi/.config/nvim,
  flood gone.
- Annotate the intentional open_floating_preview monkey-patch
  (clears the now-correct duplicate-set-field).
- README: validate/add/install/disable repro + plugin-update workflow.

1 files changed, 38 insertions, 0 deletions

diff --git a/.claude/lsp-marketplace/README.md b/.claude/lsp-marketplace/README.md
new file mode 100644
index 0000000..135b0f9
--- /dev/null
+++ b/.claude/lsp-marketplace/README.md
@@ -0,0 +1,38 @@
+# local-lsp marketplace
+
+Local Claude Code marketplace holding `lua-lsp-local` — a `lua-language-server` config that roots at `~/.config/nvim`
+(via `.lsp.json` `workspaceFolder`) with the Neovim runtime as `workspace.library`, so `vim` resolves and the
+`$HOME`-root diagnostic flood is gone.
+
+Why this exists: the official `lua-lsp@claude-plugins-official` roots `lua_ls` at `$HOME`, which ignored
+`~/.config/nvim/.luarc.json` and flooded `Undefined global vim` (no IntelliSense). See memory
+`reference_claude_lua_lsp.md`.
+
+## Install / reproduce (fresh machine)
+
+`settings.json` (`enabledPlugins`, `extraKnownMarketplaces`) carries the result, but on a clean setup run, in order:
+
+```sh
+claude plugin validate /home/tvanbesi/.claude/lsp-marketplace/plugins/lua-lsp-local
+claude plugin marketplace add /home/tvanbesi/.claude/lsp-marketplace
+claude plugin install lua-lsp-local@local-lsp        # user scope
+claude plugin disable lua-lsp@claude-plugins-official # one server owns .lua
+```
+
+Then restart the session (LSP servers only start fresh on launch).
+
+## After editing this plugin
+
+Claude copies the plugin to its cache on install; source edits don't apply until:
+
+```sh
+claude plugin marketplace update local-lsp
+claude plugin install lua-lsp-local@local-lsp   # reinstall
+```
+
+(or bump `version` in `plugins/lua-lsp-local/.claude-plugin/plugin.json`), then restart.
+
+## Verify
+
+Throwaway-edit a `.lua` file under `~/.config/nvim`; the Claude `lua_ls` (`ps`-child of `claude`) log should show
+`rootUri = file:///home/tvanbesi/.config/nvim` and no `Undefined global vim`.