release: v0.6.0 — security audit fixes + 7 new features

Audit corrections (security, concurrency, stability):
- chat_engine: bound resp.Choices[0] access, release tool slot per-iteration
- conversation_multi: synchronous save under existing lock (was racy fire-and-forget)
- workflow/engine: short-circuit on failed deps (no more infinite busy-wait); track failed/skipped status
- handlers_workflow: rune-aware truncate for plan goal (UTF-8 safe)
- server: CORS limited to localhost origins (was wildcard)
- handlers_info / terminal: mask API keys and SSH passwords as "***" in GET responses; preserve stored secret if "***" sent on update
- terminal: sshpass uses -e + SSHPASS env var (was both -p and -e)
- handlers_chat: MaxBytesReader 50 MB on /api/chat
- image_cache: 10 MB cap per image
- handlers_config: font size <= 72; profile-save unmarshal errors propagated
- handlers_info: /lsp/auto-install ProjectDir restricted to user home
- Shell.jsx: parenthesized resize-condition (operator precedence)
- orchestrator_test: CleanAIResponse capitalization (fixes failing vet)

New features:
- platform: detect OS name (Debian, Ubuntu, Windows 11, macOS X.Y) and inject in Studio system prompt next to the date
- agents: default timeout 30 min for crush_run/claude_run (cap also 30 min)
- agents: new cwd, wsl_distro, wsl_user params; on Windows hosts launch via "wsl -d <distro> -u <user> --cd <cwd> --"
- agents: new claude_run tool (mirror of crush_run for Claude Code CLI)
- terminal: list installed WSL distros individually in new-tab menu (Windows only)
- studio: system prompt rewritten around BMAD-METHOD personas + mandatory delegation template
- studio: "Réflexion avancée" toggle — inactive provider produces a preliminary report injected as [RAPPORT PRÉALABLE] context for the active provider
- studio: "Historique compressé" toggle — collapses past tool calls to last action only, with "Tout afficher" expansion

internal/api/image_cache.go

@@ -37,6 +37,9 @@ func saveImage(dataURI, filename, mimeType string) (string, error) {
 	if err != nil {
 		return "", fmt.Errorf("base64 decode: %w", err)
 	}
+	if len(decoded) > 10*1024*1024 {
+		return "", fmt.Errorf("image too large (max 10MB)")
+	}
 
 	id := fmt.Sprintf("%d-%d", time.Now().UnixMilli(), atomic.AddUint64(&imageCounter, 1))
 	ext := ".png"