feat: free-form sessions, rename/end from the panel, live Claude Context (0.2.0)

- Sessions no longer need a project folder: any name works and starts in
  DEVDESK_DEFAULT_DIR unless it matches a project; `devdesk new NAME [PROJECT]`.
- Rename (✎) and end/forget (×) sessions from the Sessions panel, plus
  `devdesk rename`. The browser runs them as `devdesk attach --new|--rename|--end`
  through ttyd. Renames keep the running Claude and its recorded conversation:
  the hook, the run-wrapper and the statusline ask tmux for the current name.
- Claude Context panel is live: devdesk-statusline snapshots model,
  context-window use, cost and edits per session, which --list reports;
  Claude's footer gets a one-line summary. The panel now sits under Sessions.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

libexec/devdesk-statusline

@@ -0,0 +1,48 @@
+#!/bin/bash
+# Claude Code statusLine command (wired in via claude-settings.json). Claude pipes
+# its status JSON in on every update; we keep a snapshot per DevDesk session for
+# the web UI's Claude Context panel and print a one-line status for Claude's footer.
+# Runs often while Claude streams, so it stays cheap and never fails loudly.
+
+input=$(cat)
+
+session=""
+if [ -n "${TMUX:-}" ] && [ -n "${TMUX_PANE:-}" ]; then
+    session=$(tmux display-message -p -t "$TMUX_PANE" '#S' 2>/dev/null)
+fi
+session=${session:-${DEVDESK_SESSION:-}}
+
+if [[ $session =~ ^[A-Za-z0-9][A-Za-z0-9_-]{0,63}$ ]]; then
+    dir="${DEVDESK_STATE_DIR:-/var/lib/devdesk}/context"
+    if mkdir -p "$dir" 2>/dev/null && tmp=$(mktemp "$dir/.$session.XXXXXX" 2>/dev/null); then
+        if jq -cM '{
+            updated: (now | floor),
+            claude_session_id: .session_id,
+            model: .model.display_name,
+            model_id: .model.id,
+            effort: .effort.level,
+            used_pct: .context_window.used_percentage,
+            window: .context_window.context_window_size,
+            used_tokens: (.context_window.current_usage
+                | if . then ((.input_tokens // 0) + (.cache_creation_input_tokens // 0)
+                             + (.cache_read_input_tokens // 0)) else null end),
+            cost_usd: .cost.total_cost_usd,
+            lines_added: .cost.total_lines_added,
+            lines_removed: .cost.total_lines_removed
+        }' <<<"$input" >"$tmp" 2>/dev/null; then
+            mv -f "$tmp" "$dir/$session.json"
+        else
+            rm -f "$tmp"
+        fi
+    fi
+fi
+
+# Footer line, in TDS colours: session · model · context % · cost
+jq -rM --arg s "$session" '
+    def c($rgb; $t): "\u001b[38;2;\($rgb)m\($t)\u001b[0m";
+    def pct: if . == null then "—" else "\(. | floor)%" end;
+    [ (if $s != "" then c("255;107;0"; "◈ \($s)") else empty end),
+      c("0;212;255"; .model.display_name // "Claude"),
+      c("127;163;191"; "ctx \(.context_window.used_percentage | pct)"),
+      c("62;96;122"; "$\((.cost.total_cost_usd // 0) * 100 | round / 100)")
+    ] | join(c("62;96;122"; " · "))' <<<"$input" 2>/dev/null || true