[iuyo5678]

Extension 0.4.3 removes unused migration flags, version comparisons, startup/install hooks and temporary rollout messages. Unpaired connections remain usable; existing pairing keys, saved recovery candidates and the explicit skip preference are retained.

Fresh and upgraded profiles follow the same optional-pairing rule. Active or pending pairings still require verification and never automatically downgrade. Real-process tests cover a released 0.4.1 daemon, rejected links preserving unpaired use, successful activation, reconnect/rotation/revocation, delayed candidate recovery and refusal to downgrade after pairing.

There is no Required-mode rollout prerequisite or enforcement cutoff. The earlier 0.4.2 implementation also supports optional pairing and is separately validated.

Validation across the final stack:

• Rust workspace: 1,020 passed, one existing ignored; formatting and strict Clippy.
• Extension: 3,570 passed, 363 environment-dependent skips; TypeScript, Biome and production build.
• Five real-daemon tests using the current CLI and published 0.4.1; real Chrome for Testing pairing/navigation smoke.
• The 0.4.2 stage independently passed 131 focused tests, three real-daemon tests, typecheck and Biome.

Stack 9/9; base: #431. Review order: #424 → #425 → #426 → #427 → #428 → #429 → #430 → #431 → #432.