content: create demo vault with splash art and feature showcase pages

8 files: index.md with wiki-links, features overview, navigation guide,
markdown showcase (all constructs), about page, changelog, and two
guides (sysop handbook, writing content) in a subdirectory. Includes
ANSI art splash.txt for the index page header.

vault/changelog.md

@@ -0,0 +1,64 @@
+---
+description: Version history and release notes
+---
+
+# Changelog
+
+All notable changes to BBS-MD are documented here.
+
+## v1.0.0 — 2026-03-01
+
+The initial release. Four phases of development, ten plans executed.
+
+### Phase 1: Safety Foundation
+
+- Panic hook restores terminal state before unwinding
+- SIGHUP and SIGTERM signal handlers for graceful shutdown
+- Login shell detection (`argv[0]` dash prefix)
+- TOML configuration via `bbs.toml`
+- Double Ctrl+C quit confirmation (critical for login shell mode)
+
+### Phase 2: Vault Core and Rendering
+
+- Full GFM markdown rendering pipeline via pulldown-cmark
+- Syntax-highlighted fenced code blocks with box-drawing borders
+- Tables with aligned columns and full grid borders
+- Scrolling with j/k, arrow keys, PgUp/PgDn
+- Error screens for missing or unreadable documents
+- Terminal resize re-rendering
+
+### Phase 3: Navigation and Links
+
+- Wiki-link resolution (`[[Page Name]]` to `page-name.md`)
+- Standard markdown link following (`[text](path.md)`)
+- Browser-style back/forward navigation history
+- Modal link cycling with Tab to enter, Up/Down to navigate
+- Draw-time REVERSED highlight on selected links
+- Breadcrumb path display in status bar
+- Broken wiki-link detection at render time (red strikethrough)
+
+### Phase 4: BBS Polish and Live Content
+
+- ANSI art splash screen on index.md via `splash.txt`
+- File metadata in status bar (last modified date, file size)
+- Virtual `[[Directory]]` page with tree view of all vault files
+- Live filesystem watching with 300ms debounce auto-refresh
+- Arrow key navigation (Left/Right for back/forward)
+- Frontmatter description display in directory listing
+
+---
+
+## Roadmap
+
+Future ideas (not yet planned):
+
+- Theming support (different color palettes)
+- Search across vault documents
+- Bookmarks and favorites
+- Multi-vault support
+- SSH server built-in (no external sshd needed)
+- User authentication and access control
+
+---
+
+Back to [[index|home]] or see [[About]].