fix(configure): re-assert cooked terminal mode every tick during the wait loop

[hyoshi]

Summary

Follow-up to #227 (PR #230): Ctrl+C could still go dead during a configure session. The merged fix forced cooked mode once before blocking on the stop event, but a configure action handled on the HTTP thread can run plugin code that re-flips the TTY into raw mode (ISIG off) while the main thread is already blocked — a one-shot pre-wait fix cannot recover from that, and the operator is stranded again. Reproduced in the field right after using the configure UI.

Fix

run_configure_wizard now re-asserts cooked mode on a 1-second cadence instead of once: the single stop_event.wait(timeout_seconds) becomes a deadline-bounded loop that waits in min(_COOKED_REASSERT_SECONDS, remaining) slices and calls force_cooked_mode(fd) every tick. Any mid-session raw-mode leak self-heals within one tick, so Ctrl+C reliably delivers SIGINT for the whole session.

Properties (review-verified):

• Stop responsiveness unchanged: stop_event.wait returns immediately when /api/shutdown or the signal handler sets the event — no full-tick delay.
• Timeout never overshoots: deadline computed once from time.monotonic(); the final slice is clamped to the residual; timeout_seconds <= 0 exits without spinning.
• The per-tick tcgetattr/tcsetattr pair costs microseconds and is OR-only (never clears bits), so an already-cooked terminal is untouched; non-TTY stdin stays a no-op.

Verification

Real-pty end-to-end repro: spawn the wizard on a pty, flip the pty to raw (ISIG/ICANON/ECHO cleared) from another thread mid-wait, send \x03 after >1 tick — SIGINT is delivered, the stop handler fires, and the wizard shuts down cleanly.

Test plan

• tests/test_web_server.py — new test_reasserts_cooked_mode_during_wait (shrinks the tick to 0.05s, asserts ≥4 force calls over a 0.4s wait; the mock is what is counted, so the loop is exercised identically on Windows); existing one-shot test relaxed to ≥1
• 30 tests pass in test_web_server.py; ruff + black clean
• CI green on the PR