Add writer-first workspace opening flow

[sigilabcodex]

Purpose

Add a GUI flow that lets a non-technical writer open an external folder, review detected projects, and enter a Workspace Map without needing to understand Git, YAML, repository roots, or scanner internals.

This should build on the read-only scanner and workspace manifest work.

Desired flow

1. User chooses “Open Workspace”.
2. User selects a folder.
3. TRURL scans it read-only.
4. TRURL shows detected projects as writer-facing cards.
5. User can review warnings and labels.
6. User enters a Workspace Map.
7. Optional manifest generation can come later, after review.

Writer-facing vocabulary

Use friendly terms by default:

• Git status → Estado de cambios
• Commit → Guardar versión
• Branch → Línea de trabajo
• Diff → Qué cambió
• Stash → Guardar aparte
• Pull/push → Sincronizar
• YAML/frontmatter → Datos del texto
• Path → Ubicación
• Repo → Proyecto versionado
• LLM prompt → Encargo a asistente
• Agent run → Trabajo asistido

Acceptance criteria

• “Open Workspace” screen or entry point exists.
• Scanner results render as project cards.
• Warnings are understandable without developer vocabulary.
• No file writes occur during opening.
• Existing demo workspace still works.
• Advanced diagnostics remain available but are not the default view.

Product principle

TRURL should feel like a calm local writing studio, not a VS Code skin or a Google Docs clone with AI. Git and agents should remain inspectable underneath, but should not dominate the writer's first experience.