docs: add Session Viewer and expand Recording Library documentation

- Document Session Viewer: split-pane layout, step editing, screenshot preview
- Add export formats table (Markdown, AI Prompt, GitHub Issue, JSON)
- Expand Recording Library with status badges and detailed action descriptions

Author: codeitlikemiley

README.md

@@ -102,15 +102,46 @@ Recording_2026-03-15_04-30-00_frames/       # Extracted key frames (PNG)
 | `_workflow.json` | AI-generated workflow with titled steps, descriptions, and frame references |
 | `_frames/` | Key frames extracted from the video, used as context for AI analysis |
 
+## Session Viewer
+
+After a recording is processed, the **Session Viewer** opens automatically. You can also reopen any past session from the Recording Library.
+
+The viewer is a split-pane interface:
+
+- **Steps Panel** (left) — AI-generated step-by-step workflow with numbered steps, action types, and descriptions
+- **Screenshot Preview** (right) — Key frame for the selected step, synced to your selection
+- **AI Prompt Tab** — View or copy the raw prompt used for AI analysis
+
+### Editing Steps
+
+Steps are fully editable inside the viewer:
+
+- **Edit** title and description inline
+- **Reorder** steps via drag-and-drop
+- **Delete** steps you don't need
+
+### Exporting
+
+Click **Export** in the title bar to copy or save the workflow:
+
+| Format | Description |
+|--------|-------------|
+| **Markdown Steps** | Full document with steps, screenshots, and metadata |
+| **AI Agent Prompt** | Ready-to-paste prompt for Cursor, Copilot, Codex, etc. |
+| **GitHub Issue** | Issue body with task checklist and context |
+| **JSON Workflow** | Machine-readable workflow for automation |
+
+Export to clipboard or save to file — all formats are supported.
+
 ## Recording Library
 
 Access all past recordings from the menu bar via **📚 Recording Library**.
 
-- **Browse** — View all recordings with thumbnails, dates, duration, and AI status
-- **Open** — Double-click or hit the eye icon to open any session in the Session Viewer
-- **Re-process** — Re-run AI analysis with a different provider or updated settings (reuses existing frames)
-- **Delete** — Remove a recording and all its associated artifacts (session, workflow, frames)
-- **Reveal in Finder** — Jump to the file in Finder
+- **Browse** — View all recordings with thumbnails, dates, duration, and status badges (`Steps Generated`, `Unprocessed`, `Processing`, `Failed`)
+- **Open** — Double-click or hit the eye icon to load the session in the Session Viewer
+- **Re-process** — Re-run AI analysis with a different provider or updated settings (reuses existing frames, skips re-extraction)
+- **Delete** — Remove a recording and all its associated artifacts (video, session, workflow, frames) with confirmation
+- **Reveal in Finder** — Jump to the recording file in Finder
 
 ## Documentation