restructure: move backend/ and layout/ into src/; convert README to org syntax; fix demo package conflict and alien-sap ioctl; update ROADMAP with v0.15.0; remove stale files

- Move backend/ and layout/ directories into src/
- Update all path references in ASD, scripts, docs
- Convert README.org from Markdown syntax to proper Org-mode
- Fix demo.lisp use-package conflict (both backend and input export #:read-event)
- Fix modern-backend TIOCGWINSZ ioctl alien type (alien-sap wrapper)
- Add v0.15.0 section to ROADMAP, update line count to 5760
- Add known gaps (suspend/resume-backend, slot modes) to v1.0.0 checklist
- Remove docs/plans/, debug-layout.lisp, system-index.txt, ci-watchdog.sh
- Move tangle.py to Hermes skill (org-babel-tangle)
- Add .gitignore for fasl files

docs/ROADMAP.org

@@ -142,7 +142,49 @@ DONE. Enhance mouse support with drag-to-select and link clicking.
 - Copy-to-clipboard via xclip/wl-copy/pbcopy
 - ~80 lines
 
-** v1.0.0: Release
+** v0.15.0: Bug fixes, demo rewrite, verification, tangle tooling
+
+DONE. Demo rewrite with interactive tabs, critical bug fixes, and
+quality-of-life infrastructure.
+
+- Demo (demo.lisp): full rewrite with Console, Components, Layout,
+  Events tabs — tab navigation, scrollbox with hot-reload, layout
+  visualization with live row/column swapping, event logging panel
+- Demo uses backend-size instead of hardcoded 80x24
+- Box title rendering: modern and simple backends now render titles
+  with title and title-align parameters
+- Cursor rendering: text-input cursor renders as solid block at
+  cursor position
+- Arrow key fix: demo arrow keys on Widgets tab no longer steal
+  focus from tab bar
+- read-raw-byte buffer fix: sb-sys:with-pinned-objects + vector-sap
+  for proper sb-posix:read buffer (SBCL type error with plain arrays)
+- EOF detection: read-raw-byte returns (values nil :eof) on stdin
+  EOF, not nil — prevents 100% CPU busy-spin on pipes
+- Escape key: 50ms timeout in read-escape-sequence to disambiguate
+  lone Escape from escape-prefixed sequences
+- confirm-dialog: fix option plist comparison (was comparing
+  objects, not keys)
+- mouse-event: button slot type changed from keyword to (or keyword
+  null)
+- tangle tooling: replace Emacs org-babel-tangle with pure-Python
+  script (scripts/tangle.py, later moved to Hermes skill)
+- Verification: verify-api.py (API smoke tests), verify-demo-pty.py
+  (PTY-based demo verification — 17 checks)
+- tangle.py fix: write-once-then-append logic (was always-appending,
+  triplicating files)
+- Org/Lisp sync: verified — 483+57+17 checks pass on fresh tangle
+- Project restructure: move backend/ and layout/ into src/
+- .gitignore for compiled fasl files
+- ~500 lines of changes across the codebase
+- Version: v0.15.0 (current)
+
+Known gaps from earlier phases:
+- suspend-backend / resume-backend (in ARCHITECTURE.org protocol
+  spec but never implemented)
+- Slot modes (defslot :mode parameter planned but not implemented)
+
+** v1.0.0: Release (target — not yet released)
 
 All phases integrated and tested. Applications can build rich terminal UIs
 from the component library without writing custom escape sequences.
@@ -158,6 +200,8 @@ Checklist:
 - [X] Rendering pipeline (v0.13.0)
 - [X] Mouse improvements (v0.14.0)
 - [X] Org/Lisp sync verified (first tangle produces no regressions)
+- [ ] Suspend/resume-backend protocol methods (ARCHITECTURE.org spec)
+- [ ] Slot modes (defslot :mode parameter)
 
 ** Feature Reference
 
@@ -177,5 +221,6 @@ Checklist:
 | 10    | Terminal capability detection          | ~100   | v0.12.0 | DONE   |
 | 11    | Rendering pipeline (framebuffer diff)  | ~250   | v0.13.0 | DONE   |
 | 12    | Mouse improvements (selection, links)  | ~80    | v0.14.0 | DONE   |
+| 13    | Bug fixes, demo rewrite, verification  | ~500   | v0.15.0 | DONE   |
 |-------+----------------------------------------+--------+---------|--------|
-|       | Total                                  | ~2800  |         |        |
+|       | Total                                  | ~5760  |         |        |