Carry project memory in the repo, with tools/memory-sync.sh

Claude Code keeps per-project memory at <home>/.claude/projects/<key>/,
where <key> is the project's absolute path with every separator and the
drive colon turned into a dash. That makes it both rename-fragile and
machine-specific, and this project has hit each of those once:

  - D:\DEV\Schunix -> D:\DEV\SchOS changed the key, and 43 memories were
    invisible until moved across by hand.
  - Development happens from Windows and from Linux, and each looks in a
    different place for the same checkout.

Committing .claude/memory/ fixes both -- git carries it across renames
and between hosts -- and `import` puts it wherever the local machine
expects. .claude/settings.local.json stays ignored: those are per-machine
permissions.

The colon maps to a dash rather than being dropped. Deleting it gives
D-DEV-SchOS, which matches nothing and silently finds zero memories; that
was the first attempt. On Git Bash the key comes from `cygpath -w`,
because Claude Code is a Windows program and sees D:\DEV\SchOS, not
/d/DEV/SchOS.

.claude/memory/schunix-console-tty.md

@@ -0,0 +1,67 @@
+---
+name: schunix-console-tty
+description: "The console has an ANSI parser, real termios and UTF-8; the font is CP437 not Latin-1, and five bugs that looked like broken commands"
+metadata: 
+  node_type: memory
+  type: project
+  originSessionId: a665e14b-86bd-4b41-a228-51377f3e9225
+  modified: 2026-08-04T21:10:44.835Z
+---
+
+**`kernel/core/console.c` was rewritten on 2026-08-04**: ANSI escape parser,
+real termios, signals, and UTF-8.
+
+**The serial line and the framebuffer are treated differently on purpose.**
+Escapes are passed through to serial verbatim -- a real terminal emulator is
+on the other end and understands them better than we ever will -- and
+*interpreted* only for the framebuffer. So a serial transcript can never tell
+you whether the escape parser works; it holds the raw bytes either way. Use
+`pwsh -File tools/ttyshot.ps1`, which drives colour/cursor/erase/UTF-8 and
+screendumps the result.
+
+**The font is CP437, not Latin-1.** `include/font.h`'s per-glyph comments
+label index N with Unicode codepoint N, which is fiction above 127: index 0xE9
+is annotated "e-acute" and draws a capital theta. Trusting it turned "café"
+into "caf" + theta. `console.c` maps Unicode through `latin1_to_cp437[]` plus
+a small table of box-drawing characters. **Verify glyphs by rendering the
+bitmap, never by reading the comment.**
+
+`font_data` was also declared `[128][16]` while containing 256 glyphs, so the
+compiler silently discarded the entire upper half -- the wall of "excess
+elements in array initializer" warnings was that.
+
+**Five bugs that all presented as broken commands, none of which were:**
+
+- `ls /bin | wc -l` said 48 instead of 240 -- `sys_ioctl` answered *every*
+  unrecognised request with 0, so `TIOCGWINSZ` on a pipe "succeeded" and every
+  program thought pipes were terminals. It returns `-ENOTTY` now. isatty() is
+  built on this call, so the blast radius was everything.
+- `yes | head -2` failed with "Invalid argument" -- `readv`/`writev` capped
+  iovcnt at 16 (POSIX's minimum) and toybox's `yes` builds 256. Now
+  `UIO_MAXIOV` = 1024, Linux's value.
+- `cat big | head -c 4` killed the shell at `rip 0x1` -- **SIG_IGN is handler
+  value 1**, and `deliver_signals()` only skipped 0 (SIG_DFL), so it jumped to
+  address 1. Nothing sent SIGPIPE until pipes learned to, at which point every
+  shell that ignores SIGPIPE died.
+- Pipes returned a bare `-1` with no signal on a closed read end; now SIGPIPE
+  plus `-EPIPE`.
+- Ctrl-C did `proc->killed = 1`, and `proc` in an interrupt handler is
+  whatever was running on that CPU -- almost never the foreground job. It
+  sends a real SIGINT to `tty_fg_pgrp` now.
+
+**Control characters must never reach the glyph path.** `vga_putc` had no tab
+case, so `'\t'` fell through to `vga_draw_char(9)` -- CP437 glyph 9 is a
+hollow circle, so pressing Tab printed a circle. The font has a picture for
+every control code and none of them is what the character means. Tab now
+advances to the next eight-column stop (erasing as it goes, so it overwrites
+rather than skipping); everything else below 0x20 is dropped.
+
+termios is real: TCGETS returns what was last set, TCSETS is honoured, and the
+console implements ICANON, ECHO, ECHOE, ECHONL, ISIG, ICRNL, INLCR, IGNCR,
+ISTRIP and VMIN. Raw mode returns bytes as they arrive rather than waiting for
+a newline -- that is what zsh and any line editor need. EOF is a flag, not a
+`^D` byte stuffed into the buffer.
+
+Check with `pwsh -File tools/bootcheck.ps1 -Tty` (six assertions, including a
+real Ctrl-C against a running `sleep`). See
+[[schunix-verify-by-driving-shell]] and [[schunix-tty-fg-pgrp-coupling]].