Emdash source with visual editor image upload fix

Fixes:
1. media.ts: wrap placeholder generation in try-catch
2. toolbar.ts: check r.ok, display error message in popover

skills/agent-browser/SKILL.md

@@ -0,0 +1,139 @@
+---
+name: agent-browser
+description: Browser automation for testing and verification. Use when you need to interact with web UIs, verify visual changes, fill forms, or capture screenshots.
+---
+
+# Agent Browser Skill
+
+Fast browser automation CLI for AI agents. Use this to verify web UI changes, test interactions, and capture screenshots.
+
+## When to Use
+
+- Verify visual changes after modifying frontend code
+- Test form interactions and user flows
+- Capture screenshots for documentation or debugging
+- Inspect rendered HTML/accessibility tree
+- Debug why something isn't working in the browser
+
+## Core Workflow
+
+### 1. Open a URL
+
+```bash
+agent-browser open http://localhost:4321/
+```
+
+### 2. Take a Snapshot
+
+The snapshot command returns an accessibility tree with refs (`@e1`, `@e2`, etc.) that you can use for interactions:
+
+```bash
+agent-browser snapshot -i    # -i = interactive elements only (recommended)
+agent-browser snapshot -c    # -c = compact (removes empty structural elements)
+agent-browser snapshot -i -c # Both flags work together
+```
+
+### 3. Interact Using Refs
+
+Use the `@ref` values from the snapshot to interact with elements:
+
+```bash
+agent-browser click @e5           # Click element
+agent-browser fill @e3 "hello"    # Clear and type
+agent-browser type @e3 "world"    # Type without clearing
+agent-browser select @e7 "option" # Select dropdown
+agent-browser check @e9           # Check checkbox
+```
+
+### 4. Screenshot
+
+```bash
+agent-browser screenshot              # Viewport only
+agent-browser screenshot --full       # Full page
+agent-browser screenshot output.png   # Save to file
+```
+
+ALWAYS check the image size before attempting to load. If it is larger than 2MB, process it using a tool such as sips or ImageMagick to reduce the size. Large files cannot be loaded by your tools.
+
+## Common Patterns
+
+### Form Verification
+
+```bash
+agent-browser open http://localhost:4321/_emdash/api/setup/dev-bypass?redirect=/_emdash/admin/content/posts/new
+agent-browser snapshot -i   # Check what fields are visible
+agent-browser fill @e3 "Test Title"
+agent-browser fill @e5 "Test content here"
+agent-browser click @e7     # Save button
+```
+
+### Get Element Info
+
+```bash
+agent-browser get text @e1      # Get text content
+agent-browser get html @e1      # Get inner HTML
+agent-browser get value @e2     # Get input value
+agent-browser get url           # Current URL
+agent-browser get title         # Page title
+agent-browser get count "button" # Count matching elements
+```
+
+### Check Element State
+
+```bash
+agent-browser is visible @e1
+agent-browser is enabled @e2
+agent-browser is checked @e3
+```
+
+### Find by Role/Label
+
+```bash
+agent-browser find role button click --name "Submit"
+agent-browser find label "Email" fill "test@example.com"
+agent-browser find placeholder "Search..." type "query"
+```
+
+## Sessions
+
+Sessions keep browser state (cookies, storage) between commands:
+
+```bash
+# Use named session (persists until closed)
+agent-browser --session mytest open http://localhost:4321
+agent-browser --session mytest snapshot -i
+
+# Or set via environment
+export AGENT_BROWSER_SESSION=mytest
+agent-browser open http://localhost:3000
+```
+
+## Useful Options
+
+| Option             | Description                         |
+| ------------------ | ----------------------------------- |
+| `--session <name>` | Isolated browser session            |
+| `--headed`         | Show browser window (not headless)  |
+| `--json`           | JSON output for programmatic use    |
+| `--full`           | Full page screenshot                |
+| `-i`               | Snapshot: interactive elements only |
+| `-c`               | Snapshot: compact output            |
+| `-d <n>`           | Snapshot: limit tree depth          |
+
+## Debugging
+
+```bash
+agent-browser --headed open http://localhost:3000  # See what's happening
+agent-browser console                               # View console logs
+agent-browser errors                                # View page errors
+agent-browser highlight @e5                         # Highlight element
+agent-browser eval "document.title"                 # Run JS
+```
+
+## Tips
+
+1. **Always snapshot first** - Get refs before interacting
+2. **Use `-i` flag** - Interactive-only snapshots are much cleaner
+3. **Wait when needed** - Use `wait <ms>` or `wait <selector>` after actions that trigger loading
+4. **Sessions for auth** - Use named sessions to persist login state
+5. **Headed for debugging** - Use `--headed` when things aren't working as expected