feat: bug fixes, lazy.nvim-style controls, auto-update checking, repo polish

Phase 1 - Bug fixes:
- Fix extmark rendering in text.lua (table vs string hl handling)
- Fix timer leak: WinClosed autocmd now triggers view.close()
- Add GOBIN/GOPATH/~/go/bin awareness to is_installed() and new bin_path()
- Reject update_all() while tasks running (race condition fix)
- Implement _toggle_details with full binary info expansion

Phase 2 - Lazy.nvim-style controls:
- U = Update all, u = update cursor binary
- I = Install all missing, i = install cursor binary
- x = Abort, CR = toggle details, q/Esc = close
- Line-to-binary mapping for cursor-aware actions

Phase 3 - Auto-update checking:
- New checker module with go list/go version -m integration
- auto_check config option (daily/weekly/custom frequency)
- Persistent state in stdpath('data')/glaze/state.json
- :GlazeCheck command for manual checks
- Update indicators in UI (version info + arrows)

Phase 4 - Repo polish:
- MIT LICENSE file
- Doughnut-themed README with badges and Why Glaze? section
- Updated help docs with all new features/keybinds/API

lua/glaze/float.lua

@@ -119,12 +119,18 @@ function Float:mount()
     self:close()
   end, "Close")
 
-  -- Auto-close on WinClosed
+  -- Auto-close on WinClosed — also trigger view cleanup to stop timer
   vim.api.nvim_create_autocmd("WinClosed", {
     pattern = tostring(self.win),
     once = true,
     callback = function()
-      self:close()
+      -- Trigger view close to clean up timer
+      local ok, view = pcall(require, "glaze.view")
+      if ok then
+        view.close()
+      else
+        self:close()
+      end
     end,
   })