One firmware: the Debug Console in every build, off until switched on, with the device's own token

There is no Debug Build any more (ADR 0010, issue #68, Q188 to Q195). The
console and the test commands are compiled into every firmware. It listens
only while Settings > Debug Console is on, which isn't the default; off,
neither its task nor its 4 KB ring exists. The token is made by the device
and shown on that page; a client proves it knows it by answering a challenge
with an HMAC, so it never crosses the network, and five wrong answers close
the console for a minute. DBG in the Status Bar while it listens.

Over USB serial only: debug on, debug token <value>, debug token new.
scripts/flash.sh --debug uses them to set a device up with the developer's
token. scripts/rdbg.py takes the token from -t, $RORO_DEBUG_TOKEN or the
file, answers the challenge, and fetches a release's ELF to decode a crash.

Gone: the cardputer-adv-debug environment, RORO_DEBUG, the +debug version,
scripts/debug_flags.py, update install ... force, and the rule that a Debug
Build doesn't install releases. Old clients and old firmwares don't talk to
each other.

Against the builds it replaces: 30 KB more flash and 88 bytes more static
RAM than the release, 4 KB less RAM than the Debug Build. 468 host tests.
Checked on the device: off by default, login, the pause after wrong tokens,
Safe Mode with the console, the setting surviving an update, debug off.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01EhqxQ49eCju4CzKYNjZzwT

.gitea/workflows/ci.yml

@@ -1,7 +1,7 @@
 # CI and releases (docs/milestones/R1.md).
 #   A push to main:    the host tests, with their coverage of lib/, and the README's badges
 #                      published to the branch `badges`.
-#   A pull request:    the same tests and coverage, then the release firmware and the Debug Build.
+#   A pull request:    the same tests and coverage, then the firmware.
 #                      A branch's pushes run nothing by themselves: its pull request runs, once.
 #   A tag v*:          all of it, then a Gitea release with the signed Update File.
 #   Run by hand:       the release of a tag that exists already (the ones from before CI).
@@ -59,7 +59,7 @@ jobs:
         if: github.event_name != 'workflow_dispatch'
         run: scripts/coverage.sh
 
-      - name: The release firmware and the Debug Build
+      - name: The firmware
         if: github.event_name == 'pull_request' || github.ref_type == 'tag'
         run: scripts/ci.sh builds