Implements StartupSeq with scan_line() that detects 2+ trust keywords
("trust", "Allow", "continue", "folder", "permission", "proceed") on a
PTY output line and returns CR to dismiss the dialog. Includes idle
fallback (0.8 s after 200+ bytes) and hard timeout (45 s / <200 bytes →
HardTimeout). Phase 2 injects the prompt via bracketed paste after a
2 s post-dismiss idle.
11 test_trust_dialog_* integration tests cover keyword match, threshold,
case sensitivity, chunk-boundary assembly, one-shot dismiss, and CR- vs
LF-terminated lines. 12 unit tests in startup::tests cover scan_line
and feed() in isolation.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
