feat(console): list/regex read_until, serial error clarity; v0.3

read_until:
- 'expected' now accepts a list of values (succeeds on any match).
- new 'regex: true' flag: each pattern is a Python regex (re.search over a
  bounded tail, Console.REGEX_WINDOW). Reports which pattern matched.

Serial console robustness & clarity:
- failed open() raises a clear ETUMRuntimeError ("Serial device '…' does not
  exist." / permission hint) instead of a raw pyserial traceback.
- a console whose open failed is safely "not open" (init _thd=None +
  isOpened guards in readchar/read_nowait/close) — no more cascading
  AttributeError: '_thd' on subsequent read steps.
- action handlers: one-liner for expected (ETUMRuntimeError) errors, full
  traceback kept for unexpected ones. All console errors use testium
  exceptions (ETUMRuntimeError).

Flatpak: grant --device=all so serial adapters (/dev/ttyUSB*, /dev/ttyACM*)
are visible in the sandbox.

Validation: new read_until list/regex (match + no-match) cases in
items/console/test.tum.

Version: 0.3.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

package/flatpak/org.testium.Testium.yaml

@@ -11,7 +11,11 @@ finish-args:
   - --share=ipc
   - --socket=fallback-x11
   - --socket=wayland
-  - --device=dri
+  # Expose all host devices to the sandbox. testium is a hardware-in-the-loop
+  # test tool: the console item must reach serial adapters (/dev/ttyUSB*,
+  # /dev/ttyACM*, …) which are otherwise invisible in the sandbox. --device=all
+  # also covers the GPU (supersedes --device=dri).
+  - --device=all
   - --share=network
   - --filesystem=home
   - --filesystem=/tmp