fix: route captured network decisions through Tessera

[Richie Gomez (richiemsft)]

📖 Description

Routes direct ProcessContainer denial-capture traffic through Tessera so WFP Learning Mode can observe the policy decision without weakening enforcement.

• Synthesizes internetClient only for direct directional captureDenials requests.
• Keeps the serialized PSEC egress policy authoritative.
• Deliberately excludes runtime proxy mode from the synthesized direct-egress capability.
• Adds regression coverage for direct and proxy postures and shared capability helpers.

This is PR 3 of 4 in the WFP Learning Mode stack. Its base is the decoder-layer branch.

🔗 References

Related to #1286.

Depends on the preceding decoder PR in this stack.

🔍 Validation

• cargo test -p mxc-sdk --lib 'capture_denials_' — 25 passed.
• cargo test -p mxc-sdk --lib 'network_policy_helpers::tests::' — 5 passed.

✅ Checklist

• Signed the Contributor License Agreement
• Linked to an issue
• Updated documentation (covered by the following documentation PR)
• Updated Copilot instructions (not applicable)
• If this PR changes Cargo.lock, the dependency-feed-check check passes (not applicable)

📋 Issue Type

• Bug fix
• Feature
• Task

🧱 Stack

1. feat: prefer option-aware Learning Mode trace startup #1417 — API startup and compatibility
2. feat: decode WFP Learning Mode network events #1418 — WFP event decoding
3. fix: route captured network decisions through Tessera #1419 — ProcessContainer integration
4. docs: describe WFP denial capture #1420 — Documentation

Review and merge in this order.

Microsoft Reviewers: Open in CodeFlow

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[Gudge (MGudgin)]

Verified review notes

The substantive issue is treating the normalized network_egress Option as evidence that a caller explicitly requested egress; the second comment asks for a negative control on the separate no-capture guard. This is a comment-only review, not a change request.

Verified clean: GitHub's patch matches the local delta. The new tests preserve the proxy posture and prove that the default-deny egress table is still serialized. ensure_capability avoids duplicate capability strings. The runner gains only two new tests (48 to 50); neither covers a parsed request with absent or ingress-only network policy. I did not reproduce a brokered-DNS/Tessera bypass on a PSEC host and am not asserting one.

Verified pre-existing — not attributed to this PR

src/mxc-sdk/src/core/mxc_common/network_parser.rs:159-175 is byte-identical at base and head. Its normalization of absent egress to Some(default) is not itself charged to this PR; the new gate's reliance on presence is the introduced defect. The existing egress-rule serializer and guarded AppContainer capability helper are also unchanged and are not being treated as regressions.

[Richie Gomez (richiemsft)]

Gudge (@MGudgin) The remaining capability-presence finding is fixed in a01d125. network.egress absence now remains distinct through parsing, and the parse-to-PSEC matrix covers absent network, ingress-only, explicit deny-default egress, plus the no-capture negative control. The complete mxc-sdk library run passed 2,775 tests; one unrelated host-dependent loopback proxy test timed out consistently on this machine. Please re-review the updated tip.

[Copilot]

🔵 Needs a closer look

Security-sensitive network enforcement changes depend on preceding stacked ABI and decoder changes, warranting final human validation.

0 open findings

What changed in this PR

Routes ProcessContainer denial-capture network decisions through Tessera while preserving authoritative PSEC enforcement and proxy isolation.

Changes:

• Synthesizes direct-egress capability only for eligible network-aware captures.
• Emits and validates version 5 capture diagnostics.
• Adds regression coverage for direct, proxy, and legacy postures.

File	Description
src/​tools/​wxc/​src/​audit.rs	Validates and publishes versioned verbose diagnostics.
src/​mxc-sdk/​src/​core/​mxc_common/​network_parser.rs	Preserves explicit egress-section presence.
src/​mxc-sdk/​src/​core/​mxc_common/​mod.rs	Exposes the parser within the crate.
src/​mxc-sdk/​src/​backends/​process_container/​common/​capture_output.rs	Writes version 5 native-capture diagnostics.
src/​mxc-sdk/​src/​backends/​process_container/​common/​base_container_runner.rs	Selects network-aware capture routing and decoding.
src/​mxc-sdk/​src/​backends/​process_container/​common/​base_container_helpers/​tests.rs	Updates helper invocations for capture routing.
src/​mxc-sdk/​src/​backends/​process_container/​common/​base_container_helpers.rs	Adds conditional internetClient synthesis.

🧠 Review effort: Balanced

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[Copilot]

🔵 Needs a closer look

The security-sensitive, Windows-specific interaction between capability gating, Tessera enforcement, and WFP capture warrants final human validation.

0 open findings

🧠 Review effort: Balanced