feat: formatted JSON and certificates, errors in the status pane, no scope access list (#19)

**Formatted values.** A revealed value is shown as it reads best: JSON indented, and PEM certificates as subject, issuer, valid dates, names and SHA-1 thumbprint instead of base64. Any other PEM block (a private key in a bundle) is named, `EC PRIVATE KEY (not shown)`, never shown. Anything else shows as before. `y` copies the value exactly as stored, and the hints line says so (`JSON, formatted: y copies it as stored`).

**Errors in the status pane.** This session's errors, newest first, up to 20, with the time and what they were about (`12:32 kv-restricted: 403 Forbidden: …`): lists that couldn't load, values and details that couldn't be read, sources, saving the cache, and whatever the footer flashed (a failed copy) before you moved on. A repeat moves to the top. Sign-ins aren't listed (the footer and the account say those). Only the first line of each, and not kept after quitting. `y` copies one.

**No access list for Databricks scopes.** It was the one request of its own left (one call per scope). Removed with its tests and docs; refusals still say what to check.

**Copying over SSH: checked, nothing to change.** Over SSH (`SSH_TTY`/`SSH_CONNECTION`), `y` copies with OSC 52, and the 30-second clear works the same way. Your tmux (3.7, `set-clipboard on`) passes it through and kitty (`clipboard_control write-clipboard`) accepts it; docs/config.md already says what's needed.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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Co-authored-by: Karl-Einar Bergstrøm <karl-einarb@outlook.com>
Reviewed-on: #19

internal/ui/app/status.go

@@ -102,6 +102,7 @@ func (m Model) statusFields() []panes.Field {
 	}
 
 	out = append(out, m.expiringFields()...)
+	out = append(out, m.errorFields()...)
 
 	for i, path := range m.configFiles {
 		label := ""