feat(plugin): replace Lspsaga with native LSP & Snacks integration

Why: Clean up the heavy Lspsaga UI and adopt built‑in LSP plus Snacks for better performance and maintainability.

- New Features
  - Use native `vim.lsp.buf` functions for code actions, diagnostics, rename, etc.
  - Integrate Snacks picker for definitions, references, symbols, and type definitions.
- Enhancements  - Update keybindings to use Snacks and native APIs instead of Lspsaga.
  - Drop `nvimdev/Lspsaga.nvim`, `typescript-tools.nvim`, and unused `plenary.nvim`.
  - Preserve mini.misc auto‑root and other minor improvements.
- Bug Fixes
  - Resolve broken Lspsaga UI configuration and related mappings.
  - Remove stale `<leader>la` mapping that referenced Lspsaga.

plugin/editor.lua

@@ -11,9 +11,7 @@ add({
     'numToStr/Navigator.nvim', -- navigator
     'm4xshen/hardtime.nvim', -- workflow
     'mg979/vim-visual-multi', -- multiple cursors
-    'pmizio/typescript-tools.nvim', -- typescript tools
     { src = 'iamcco/markdown-preview.nvim', build = 'cd app && npm install' },
-    'nvim-lua/plenary.nvim', -- dependency for typescript-tools
     -- 'nvim-flutter/flutter-tools.nvim', -- flutter tools
 })
 
@@ -69,27 +67,3 @@ vim.keymap.set('i', '<A-x>', function()
     return vim.fn['codeium#Clear']()
 end, { expr = true, silent = true })
 
--- typescript tools
-require('typescript-tools').setup({
-    filetypes = { 'javascript', 'javascriptreact', 'typescript', 'typescriptreact' },
-    settings = {
-        separate_diagnostic_server = true,
-        publish_diagnostic_on = 'insert_leave',
-        expose_as_code_action = {
-            'fix_all',
-            'add_missing_imports',
-            'remove_unused',
-            'remove_unused_imports',
-            'organize_imports',
-        },
-        tsserver_plugins = {},
-        complete_function_calls = false,
-        include_completions_with_insert_text = true,
-        code_lens = 'off',
-        disable_member_code_lens = true,
-        jsx_close_tag = {
-            enable = false,
-            filetypes = { 'javascriptreact', 'typescriptreact' },
-        },
-    },
-})