feat(notifications): add W66 bounded webhook runtime

[ammarheidari]

Authority

W66 / #215 typed notification destination/security foundation is protected-main admitted via PRs #240/#242.

Runtime slice scope

• concrete webhook-provider orchestration over preconfigured NotificationDestinationProfile;
• fixed safe event projection only: event ID/class/type/subject/summary/time;
• configured endpoint only — no caller-supplied URL, method, headers or redirect policy;
• endpoint re-resolution through INotificationEndpointResolutionPort and pinned endpoint binding;
• optional credentials resolved only through opaque preprovisioned NotificationCredentialBindingId;
• payload size enforced before any resolution/network boundary;
• destination event-class admission enforced before any external work;
• transport receives only the pinned endpoint, fixed JSON payload, profile revision fingerprint and optional redacted credential value;
• SHA-256 payload fingerprint returned for later durable dedup/evidence integration.

Safety

• no generic HTTP proxy;
• no arbitrary per-request endpoint;
• no raw secret locator/value in event payload;
• no caller-controlled headers;
• no redirect surface in the adapter contract;
• no retry loop, durable worker, subscription runtime or API/UI activation in this slice;
• Email/Slack/Teams/Telegram/PagerDuty remain outside this slice.

Rebased exact head: c92ed6d3fcbc6fb622a535f4c3092cbe1f27ad6d.

Refs #215 #209.

• corrected runtime-bound length validation so the W66 runtime compiles under the repository's .NET 10 quality gate.
• rebased without semantic changes onto protected-main cb2519bc853ed21da5b3e310530c6d062324ca20 after W67 PR feat(cli): extend W67 bounded read-only parity #256 admission; fresh exact-head gates/review required.

[ammarheidari]

@codex review

Please review exact head 18f5c1fa52b47f7cb1a08db6a30f7d1f7d2325e9 only. Focus on SSRF/pinning boundary preservation, endpoint substitution, credential scoping, secret exposure, payload/event bounds, cancellation, and ensuring this cannot become a caller-controlled generic HTTP proxy.

[chatgpt-codex-connector]

Codex Review Summary

This comment shows the latest Codex review activity on this pull request.

Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-10-04T21:42:36.246827Z	c92ed6d	Manual request

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[ammarheidari]

@codex review

Please review corrective exact head 428eda7cce2145abae7977d3b0b512f1db706af2 only. Verify the bounded webhook runtime remains non-proxying and preserves endpoint pinning, credential scoping, fixed event projection, payload bounds, cancellation and secret non-disclosure.

[chatgpt-codex-connector]

Codex Review: Didn't find any major issues. Bravo.

Reviewed commit: 428eda7cce

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[ammarheidari]

@codex review

Please review rebased exact head c92ed6d3fcbc6fb622a535f4c3092cbe1f27ad6d only. Tree semantics are unchanged; verify the bounded webhook runtime remains non-proxying and preserves endpoint pinning, credential scoping, fixed projection, payload bounds and secret non-disclosure.

[chatgpt-codex-connector]

Codex Review: Didn't find any major issues. Can't wait for the next one!

Reviewed commit: c92ed6d3fc

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• Mark a draft as ready
• Comment "@codex review".

If Codex has suggestions, it will comment; otherwise it will react with 👍.

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