T4 owner-cutover acceptance backlog: full 48-cell qualification matrix #1386

Migrated from bb7133/tiproxy#287. Original author: bb7133; created: 2026-09-25T14:02:29Z; source body SHA-256: b890ff25b94edab1be74aa3d0709ec5a86ce717c19c625246101bb5c20ad4577.

Backlog from the #1380 owner-cutover T4 acceptance (reduced (c) bar, accepted 2026-09-25).

Owner cutover was accepted under the reduced (c) bar: 8 rows minus deferrals — 21/21 macOS cells green (M1,M2,M3,M6,M7,M8,M9 × plain/TLS/PROXY) + M4 owner-semantics-green (memory_series → Linux, see companion issue) + M5 deferred (Linux-only).

The full 48-cell matrix was deferred:

• 9 rows M1–M9 × 5 columns (plain / TLS / PROXY / compress-zlib / compress-zstd) + 3 sentinels (tls-proxy-zstd on M1/M7/M9) = 48 physical cells (qualify-route-owner.sh --print-plan).
• Not yet run: the compression variants (C-zlib / C-zstd) on all rows, the 3 sentinels, and the entire M5 row (Linux-only, needs memory_series + cpu_series).

Task: on a Linux host with memory_series/cpu_series available, run the complete 48-cell qualify-route-owner.sh matrix and archive the evidence.

Ref #1380.