[HANCORE-linux]

Summary

• Ignore bounded surrounding ASCII whitespace when validating and redeeming pasted invites; continue rejecting interior and Unicode whitespace.
• Submit the normalized invite through the existing UI/IPC flow without visual changes.
• Canonicalize QR input and escape event output to keep JSONL valid.
• Add parser, Panel/IPC, and QR regression coverage; document the behavior.

Refs #58. The issue will be closed with a completion comment after merge.

Verification

• Passed: make test, make helper, make arch, no-signal-build, phase2, IPC regression, panel-request-focus (including Quickshell runtime), redeem-feedback, QML plaintext checks, plugin validation, and git diff --check.
• Independent code review approved the final diff; focused parser, UI/IPC, and QR checks passed.
• Known limitation: qmllint Panel.qml exits 255 without diagnostics. No live Tox/private-service test or physical QR scan.
• No live deployment performed.