fix(tunnel): restore H2 TLS session resumption

[cppla]

Summary

• Restore real TLS 1.3 session resumption for the cache-enabled fixed Chrome-133 H2 client using a fresh preset and uTLS's native PSK extension; empty/disabled caches keep full handshakes. Preparation stays inside HandshakeContext, with nonblocking cancellation checks.
• Handle the pinned library's populated-PSK + HelloRetryRequest limitation narrowly: require the exact library diagnostic and genuine exported HRR/PSK state, close and join the failed physical attempt, and retry once without a ticket under the same remaining initialization budget.
• Keep certificate/hostname verification, TLS 1.3, h2 and fresh per-physical proxy authentication. No 0-RTT, native-profile switch, global resumption disable, unrelated-error retry, dependency update or protocol-version change.

Evidence for final head 97dfb7c

• Source-attributed macOS Go 1.25.13 offline make check and full make race passed; release-recipe suites 18+17+14 passed.
• Real loopback resumption tests and policy controls pass. The original production-only negative control accurately fails enabled Chrome resumption while native/disabled/nil controls pass.
• Real P256-only HRR tests pass race ×3: two healthy authenticated physical sessions, four complete TCP payload/reply + FIN tunnels, fresh bootstrap/short continuation and distinct authentication keys. Native genuinely resumes through HRR; Chrome performs a single full-handshake compatibility fallback. Same-final tests with the earlier two-production-file candidate accurately fail the warm Chrome case.
• Boundary tests pass race ×3 (33 leaf executions): original absolute timeout, caller custom cause even when dial returns ctx.Err, client.Close, failed-old-raw close before fresh dial, fresh H2-preface cancellation, no retry loop, and no retry for certificate/ALPN/same-text-non-HRR errors. Same-final old-production negative runs compile and fail exactly the eight fallback-dependent leaves; three ordinary-error controls pass.
• One isolated cached-image Linux/arm64 CGO-disabled component run passed: 10 new top-level names ×3 (30 executions/108 RUN entries) and 40 existing names ×1 (119 RUN entries). Exact list/RUN sets and full-source/compiler/script/binary manifests match; owned container removed. This is not Linux race or production validation.
• Independent automated source/security/context reviews completed without a remaining must-fix finding. Final full Go/docs/module manifest SHA-256: 3b3747fa0f7ab76156413e7783484f5b32e87d37c620e231181ca2297bbfd26a.

The initial a106d1a head had green CI but was deliberately not merged after review identified the HRR gap. Final-head CI (11/11 jobs), CodeQL and Linux netem all completed successfully on pull_request attempt 1. Actual docker integration, dual-architecture OCI export and netem success logs were verified; no reruns. The confirmed HRR review thread was addressed and resolved.

Limits

No actual-browser comparison, corpus campaign, remote deployment, release or tag. No indistinguishability/classifier-advantage claim. HRR fallback is a full handshake, not successful Chrome PSK/HRR resumption; P384/cookie-only paths are source-reviewed but not exercised. TLS ticket reuse can correlate connections; caller-disable policy remains. All earlier intermediate failures/logs are retained locally; one opaque historical peer-close error remains unconfirmed rather than being retroactively labelled reset.

Merge verification

Squash-merged as 01b705234df2a9d8385013de35d85fad01dd1126. Local and remote main agree, tested tree and full-source manifests match, and the worktree is clean. Main push attempt1 CI (11/11 jobs), CodeQL and Linux netem all passed; actual container/dual-architecture OCI export and netem logs were checked. Post-main macOS race repeats of all 10 exact new top-level names ×3 passed (30 executions/108 RUN entries), with exact selection/RUN-set checks. No new release or tag.

[Copilot]

Copilot review overview

🟡 Changes recommended

Warm connections fail when a valid server triggers HelloRetryRequest because uTLS v1.8.2 cannot reprocess the populated PSK.

Review effort: Balanced
Findings: 1

Open (1)

• TLS 1.3 HRR fails when reprocessing a populated PSK · New

What changed in this PR

Restores TLS 1.3 session resumption for the fixed Chrome-133 H2 profile.

Changes:

• Adds uTLS-native PSK/binder preparation.
• Adds resumption, cancellation, authentication, and verification tests.
• Documents resumption privacy and certificate-policy implications.

File	Description
internal/​tunnel/​web_fingerprint.go	Adds PSK-enabled Chrome-133 handshakes.
internal/​tunnel/​web_h2_resumption_test.go	Tests real H2 resumption and fresh authentication.
internal/​tunnel/​web_fingerprint_resumption_policy_test.go	Tests preparation, cancellation, and verification policies.
docs/​WEB_COVER.md	Documents resumption behavior and limitations.

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