Remove MEAD from vim-clap (split into standalone repo)

MEAD has been extracted to its own repository at
~/src/github.com/liuchengxu/mead. This commit removes all MEAD-specific
code from vim-clap while keeping the WebSocket markdown preview intact.

Deleted:
- mead/ directory (Tauri app, now in standalone repo)
- MEAD-only JS: tauri-app, dictionary, ask-ai, settings-dialog,
  path-input, terminal, pdf-viewer
- MEAD-only CSS: dictionary, ask-ai, terminal, pdf-viewer
- vendor/ directory (PDF.js, cmaps, standard fonts)

Modified:
- assets.rs: remove Tauri mode, properly inline all CSS (fuzzy-finder,
  presentation, diff) that was previously only loaded by MEAD's build.rs
- index.html: strip MEAD panels (dictionary, AI, settings), xterm.js,
  PDF.js, MEAD branding
- Cargo.toml: remove "mead" from exclude list

Author: liuchengxu

Cargo.toml

@@ -24,7 +24,6 @@ members = [
     "crates/maple_derive",
     "crates/maple_lsp",
     "crates/maple_markdown",
-    # mead is a separate workspace (has its own Cargo.toml with [workspace])
     "crates/markdown_preview_core",
     "crates/matcher",
     "crates/matcher/extracted_fzy",
@@ -40,7 +39,7 @@ members = [
     "crates/xtask",
 ]
 
-exclude = ["pythonx/clap/fuzzymatch-rs", "mead"]
+exclude = ["pythonx/clap/fuzzymatch-rs"]
 
 default-members = ["crates/maple"]
 

crates/maple_markdown/src/lib.rs

@@ -118,7 +118,7 @@ async fn ws_handler(
             handle_websocket(ws, msg_rx, watcher_rx, disconnect_tx, base_dir).await
         })
     } else {
-        let html = Assets::build_html(&markdown_preview_core::assets::AssetOptions::default());
+        let html = Assets::build_html(&markdown_preview_core::assets::AssetOptions);
         let mut headers = HeaderMap::new();
         headers.insert(
             header::CACHE_CONTROL,