feat: v0.11.0 VS Code-like explorer, markdown preview, search in files

- Explorer: context menus, multi-select, inline rename/new, drag to move
  or copy, desktop drag-and-drop uploads (folders too), cut/copy/paste,
  duplicate, download, delete to a 7-day trash with Undo. Server side in
  libexec/devdesk-fsops.sh with bats tests. Closes #54
- Markdown preview in a shadow root: headings with anchors and outline,
  highlighted code with copy, callouts, task lists, front matter, links
  that open files, live split view. Editor status bar, multi-cursor,
  closeBrackets, Ctrl+G, tab menus and reordering. Closes #55
- Search in files (Ctrl+Shift+F) via git grep / grep. Closes #56
- Fix: nested $(...) path checks now fail hard (set -e does not reach
  them; an escape created /x in testing); newest folder listing wins;
  sessionAction returns the reply JSON.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01WHRLCCdXYm41Qx5kNhehaP

tests/attach.bats

@@ -1195,3 +1195,146 @@ JSONL
     run devdesk attach --unsplit alpha
     [ "$(jq -r .closed <<<"$output")" = 0 ]
 }
+
+fs_put() { # SESSION PATH MODE CONTENT-FILE
+    local size
+    size=$(stat -c %s "$4")
+    base64 -w0 "$4" | devdesk attach --fs-put "$1" "$2" "$size" "$3"
+}
+last_json() { tail -n1 <<<"$output"; }
+
+@test "fs-mkdir, fs-move and fs-copy stay inside the folder and never overwrite (#54)" {
+    p="$DEVDESK_PROJECTS_ROOT/alpha"
+    mkdir -p "$p/src" && printf 'a\n' >"$p/src/a.txt" && printf 'b\n' >"$p/b.txt"
+    ln -s "$TMP/outside" "$p/out"
+    ln -s b.txt "$p/link"
+    run devdesk attach --fs-mkdir alpha docs/guides
+    [ "$status" -eq 0 ] && [ -d "$p/docs/guides" ]
+    [ "$(last_json | jq -r .path)" = docs/guides ]
+    run devdesk attach --fs-mkdir alpha docs
+    [[ $output == *"already exists"* ]]
+    for bad in ../x /abs out/x 'a/../b' . '' docs/; do
+        run devdesk attach --fs-mkdir alpha "$bad"
+        [ "$status" -ne 0 ]
+    done
+    [ -z "$(ls -A "$TMP/outside")" ]
+    # out/x once escaped to /x: set -e doesn't reach into $(...) (#54)
+    [ ! -e /x ] && [ ! -e /abs ]
+
+    # rename a file, move a folder into another, never onto something
+    run devdesk attach --fs-move alpha src/a.txt src/renamed.txt
+    [ "$status" -eq 0 ] && [ -f "$p/src/renamed.txt" ] && [ ! -e "$p/src/a.txt" ]
+    run devdesk attach --fs-move alpha b.txt src/renamed.txt
+    [ "$status" -ne 0 ] && [[ $output == *"already exists"* ]]
+    [ "$(cat "$p/b.txt")" = b ]
+    run devdesk attach --fs-move alpha src docs/src
+    [ "$status" -eq 0 ] && [ -f "$p/docs/src/renamed.txt" ]
+    run devdesk attach --fs-move alpha docs docs/guides/docs
+    [ "$status" -ne 0 ] && [[ $output == *"inside itself"* ]]
+    run devdesk attach --fs-move alpha b.txt out/b.txt
+    [ "$status" -ne 0 ]
+    run devdesk attach --fs-move alpha ../outside x
+    [ "$status" -ne 0 ]
+    # a symlink moves as a link
+    run devdesk attach --fs-move alpha link link2
+    [ "$status" -eq 0 ] && [ -L "$p/link2" ] && [ -f "$p/b.txt" ]
+    # copy: folders recursively, missing parents created
+    run devdesk attach --fs-copy alpha docs/src new/place/src
+    [ "$status" -eq 0 ] && [ -f "$p/new/place/src/renamed.txt" ] && [ -f "$p/docs/src/renamed.txt" ]
+    run devdesk attach --fs-copy alpha b.txt docs/src/renamed.txt
+    [ "$status" -ne 0 ]
+}
+
+@test "fs-delete moves to the trash and fs-restore puts it back (#54)" {
+    p="$DEVDESK_PROJECTS_ROOT/alpha"
+    mkdir -p "$p/dir/sub" && printf 'x\n' >"$p/dir/sub/x" && printf 'y\n' >"$p/y.txt"
+    ln -s "$TMP/outside" "$p/out"
+    touch "$TMP/outside/keep"
+    run devdesk attach --fs-delete alpha dir y.txt out
+    [ "$status" -eq 0 ]
+    id=$(last_json | jq -r .trash)
+    [ "$(last_json | jq -c .paths)" = '["dir","y.txt","out"]' ]
+    [ ! -e "$p/dir" ] && [ ! -e "$p/y.txt" ] && [ ! -L "$p/out" ] && [ -f "$TMP/outside/keep" ]
+    # nothing deleted when one path is bad
+    printf 'z\n' >"$p/z.txt"
+    run devdesk attach --fs-delete alpha z.txt ../outside
+    [ "$status" -ne 0 ] && [ -f "$p/z.txt" ]
+    run devdesk attach --fs-delete alpha .
+    [ "$status" -ne 0 ]
+    # restore; a path taken meanwhile is refused
+    printf 'new\n' >"$p/y.txt"
+    run devdesk attach --fs-restore alpha "$id"
+    [ "$status" -ne 0 ] && [[ $output == *"already exists: y.txt"* ]]
+    rm "$p/y.txt"
+    run devdesk attach --fs-restore alpha "$id"
+    [ "$status" -eq 0 ]
+    [ "$(cat "$p/dir/sub/x" "$p/y.txt")" = "$(printf 'x\ny')" ] && [ -L "$p/out" ]
+    [ ! -e "$DEVDESK_STATE_DIR/trash/alpha/$id" ]
+    run devdesk attach --fs-restore alpha "../../etc"
+    [ "$status" -ne 0 ]
+}
+
+@test "fs-put uploads any file into a folder; fs-download returns it (#54)" {
+    p="$DEVDESK_PROJECTS_ROOT/alpha"
+    head -c 3000 /dev/urandom >"$TMP/bin"
+    run fs_put alpha assets/img/logo.bin new "$TMP/bin"
+    [ "$status" -eq 0 ] && cmp -s "$TMP/bin" "$p/assets/img/logo.bin"
+    [ "$(stat -c %a "$p/assets/img/logo.bin")" = 644 ]
+    run fs_put alpha assets/img/logo.bin new "$TMP/bin"
+    [ "$status" -ne 0 ] && [[ $output == *"already exists"* ]]
+    printf 'v2' >"$TMP/v2"
+    chmod 600 "$p/assets/img/logo.bin"
+    run fs_put alpha assets/img/logo.bin replace "$TMP/v2"
+    [ "$status" -eq 0 ] && [ "$(cat "$p/assets/img/logo.bin")" = v2 ] && [ "$(stat -c %a "$p/assets/img/logo.bin")" = 600 ]
+    : >"$TMP/empty"
+    run fs_put alpha empty.txt new "$TMP/empty"
+    [ "$status" -eq 0 ] && [ -f "$p/empty.txt" ] && [ ! -s "$p/empty.txt" ]
+    ln -s "$TMP/outside" "$p/out"
+    for bad in out/x ../x /x assets; do
+        run fs_put alpha "$bad" new "$TMP/v2"
+        [ "$status" -ne 0 ]
+    done
+    [ -z "$(ls -A "$TMP/outside")" ]
+    run fs_put alpha assets replace "$TMP/v2"
+    [ "$status" -ne 0 ] && [ -d "$p/assets" ]
+    # short stream: nothing left behind
+    run bash -c "printf aGVs | '$REPO/bin/devdesk' attach --fs-put alpha short.txt 6 new"
+    [ "$status" -ne 0 ] && [ ! -e "$p/short.txt" ] && [ -z "$(find "$p" -name '.*devdesk-*')" ]
+    # download: binary body comes back whole
+    run devdesk attach --fs-download alpha assets/img/logo.bin
+    [ "$status" -eq 0 ]
+    [ "$(sed -n '/DEVDESK-BLOB-BEGIN/{n;p}' <<<"$output" | base64 -d)" = v2 ]
+    head -c 3000 /dev/urandom >"$p/rand"
+    run devdesk attach --fs-download alpha rand
+    sed -n '/DEVDESK-BLOB-BEGIN/{n;p}' <<<"$output" | base64 -d | cmp -s - "$p/rand"
+    run devdesk attach --fs-download alpha out
+    [ "$status" -ne 0 ]
+}
+
+@test "fs-grep searches files, literally or by regex, git or not (#56)" {
+    p="$DEVDESK_PROJECTS_ROOT/alpha"
+    mkdir -p "$p/src" "$p/node_modules/x"
+    printf 'const Answer = 42;\nlet b = "a:b";\n' >"$p/src/a.js"
+    printf 'answer here\n' >"$p/node_modules/x/i.js"
+    printf '\x00\x01answer' >"$p/bin.dat"
+    run devdesk attach --fs-grep alpha - 'Answer'
+    [ "$(jq -c '[.matches[] | [.p, .l, .t]]' <<<"$output")" = '[["src/a.js",1,"const Answer = 42;"]]' ]
+    run devdesk attach --fs-grep alpha i 'answer'
+    [ "$(jq -r '[.matches[].p] | join(",")' <<<"$output")" = src/a.js ]
+    run devdesk attach --fs-grep alpha - '"a:b"'
+    [ "$(jq -r '.matches[0].t' <<<"$output")" = 'let b = "a:b";' ]
+    run devdesk attach --fs-grep alpha r 'A[n]swer = [0-9]+'
+    [ "$(jq -r '.matches | length' <<<"$output")" = 1 ]
+    run devdesk attach --fs-grep alpha - '[n]'
+    [ "$(jq -r '.matches | length' <<<"$output")" = 0 ]
+    # in a repository: git grep, .gitignore honoured, untracked files included
+    git -C "$p" init -q
+    printf 'node_modules/\n' >"$p/.gitignore"
+    printf 'Answer again\n' >"$p/untracked.txt"
+    run devdesk attach --fs-grep alpha w 'Answer'
+    [ "$(jq -c '[.matches[] | [.p, .l]] | sort' <<<"$output")" = '[["src/a.js",1],["untracked.txt",1]]' ]
+    run devdesk attach --fs-grep alpha x 'Answer'
+    [ "$status" -ne 0 ]
+    run devdesk attach --fs-grep alpha - ''
+    [ "$status" -ne 0 ]
+}