Operation Undigg: multi-syntax input, pandoc export, wiki mode, auto-themes.

Phase 1: Pandoc export pipeline — 67 output formats for threads, namespaces, nodes.
Phase 2: Multi-syntax input — accept markdown, HTML, RST, MediaWiki, LaTeX, etc.
Phase 3: Wiki mode — per-namespace toggle, revision tracking, wiki-edit endpoint.
Phase 4: Auto-generated themes — deterministic CSS per namespace, light + dark mode.

Includes unit, integration, and functional tests (95 new, 544 total).

docs/tickets/15.md

@@ -0,0 +1,120 @@
+# T15: Operation Undigg — Pandoc Export & Wiki Mode
+
+**Status**: in-progress
+**Priority**: high
+**Source**: fox directive 2026-03-09
+
+## Summary
+
+Transform remarkbox into a document-first platform. Every namespace is a book,
+every root thread is a chapter. Pandoc renders every format it can produce.
+Wiki mode lets anyone edit root topics with revision tracking.
+
+## Architecture
+
+```
+Namespace (book)           → pandoc → all formats (default)
+  └── Root Node (chapter)  → pandoc → all formats (default)
+        └── Reply (section) → pandoc → on-demand only
+```
+
+### Data model changes
+
+1. **Node.source_format** — `Unicode(16)`, default `'markdown'`. Tracks what
+   syntax the user wrote in (markdown, html, rst, mediawiki, latex, textile, etc).
+   Pandoc input formats map directly.
+
+2. **rb_revision** — new table for wiki mode edit history.
+   - `id` (UUIDType, PK)
+   - `node_id` (FK → Node)
+   - `user_id` (FK → User)
+   - `data` (UnicodeText) — raw source at time of edit
+   - `source_format` (Unicode(16))
+   - `created` (BigInteger) — timestamp
+   - `revision_number` (Integer) — sequential per node
+
+3. **Namespace.wiki** — already exists (`Boolean, default=False`), needs
+   implementation. When True, any authenticated user can edit the root node
+   of any thread. Each edit creates a revision.
+
+### Export pipeline
+
+Pandoc subprocess. Input = markdown/rst/html/whatever `source_format` says.
+Output = every format pandoc supports.
+
+**Default generated (cached on write/edit):**
+- Namespace level: one document per namespace containing all root threads
+- Root node level: one document per root thread
+
+**On-demand (generated per request):**
+- Any node or subthread at any depth
+
+**Pandoc output formats** (67 total, subset for default generation):
+- markdown, gfm, commonmark, html5, pdf, epub, docx, odt, rst,
+  mediawiki, latex, man, plain, rtf, asciidoc, textile, org, json
+
+**URI scheme:**
+```
+/api/v1/export/namespace/{name}.{format}     — full book
+/api/v1/export/threads/{node_id}.{format}    — single chapter
+/api/v1/export/nodes/{node_id}.{format}      — on-demand subthread
+```
+
+### Content ingestion
+
+On write (create thread, reply, edit):
+1. Accept `source_format` parameter (default: `markdown`)
+2. If HTML input, strip to clean body (no head/script/style)
+3. Store raw source in `Node.data` with `Node.source_format`
+4. Render to HTML via pandoc: `pandoc -f {source_format} -t html5`
+5. Sanitize HTML output through existing bleach pipeline
+6. Store in `Node.data_html`
+
+### Wiki mode
+
+When `Namespace.wiki = True`:
+- Any authenticated user can edit root nodes (not just owner/moderator)
+- Each edit stores a revision in `rb_revision` before overwriting
+- Root node always has the latest version (fast render)
+- Revision history accessible via API
+- Diff between revisions on-demand
+
+### Progressive enhancement
+
+Export menus work without JS (plain links to format URIs).
+With JS: dropdown/popover with format picker, async download.
+
+## Phases
+
+### Phase 1: Export pipeline (pandoc integration)
+- [ ] Tree-to-markdown renderer (walk node tree → single markdown document)
+- [ ] Export API endpoints (namespace, thread, node)
+- [ ] Pandoc subprocess wrapper
+- [ ] Format negotiation (URI suffix or Accept header)
+
+### Phase 2: Multi-syntax input
+- [ ] Add `source_format` column to Node
+- [ ] Alembic migration
+- [ ] Modify `set_data()` to use pandoc for non-markdown formats
+- [ ] Accept `source_format` on create/reply/edit API endpoints
+- [ ] HTML stripping for HTML input
+
+### Phase 3: Wiki mode + revisions
+- [ ] Create `rb_revision` model + migration
+- [ ] Implement wiki edit permissions in Namespace
+- [ ] Store revisions on edit
+- [ ] Revision history API endpoint
+- [ ] Diff endpoint
+
+### Phase 4: Auto-generated themes
+- [ ] Per-namespace theme generation (light + dark)
+- [ ] CSS custom properties for theming
+- [ ] Theme preview
+
+## Notes
+
+- Pandoc 3.1.3 installed at `/usr/bin/pandoc`
+- 43 input formats, 67 output formats
+- PDF requires LaTeX (`pdflatex`) or `wkhtmltopdf` — check availability
+- `Namespace.wiki` column already exists in schema, just needs implementation
+- Export cache invalidation: on any node edit in the tree

docs/tickets/index.md

@@ -19,3 +19,4 @@ Tracked issues from the meta.remarkbox.com and faq.remarkbox.com audit (2026-02-
 | [T12](12.md) | Reply to API-only CRUD thread confirming done | resolved | low | meta `6db01560` |
 | [T13](13.md) | Reply to lock/archive thread confirming done | resolved | low | meta `7e9d5864` |
 | [T14](14.md) | meta/faq SSL outage — missing proxy blocks | resolved | critical | postmortem 2026-02-25 |
+| [T15](15.md) | Operation Undigg — Pandoc export & wiki mode | in-progress | high | fox directive 2026-03-09 |