docs: reconcile package docs and articles with current behavior

[Vulthil]

Summary

Documentation truth sweep across the nuget package READMEs, the docfx articles, shipped XML doc comments, and nuget package metadata — every claim reconciled against current behavior on main. No code-behavior changes.

• Remove documented-but-nonexistent APIs: the outbox "strategy" contracts in the outbox README and relational article (real surface: IOutboxStore / RelationalOutboxStore<TContext>), a two-type-parameter AddHttpMock overload, and a per-consumer Bind routing override (real knob: UseRetry; bindings are per-queue Subscribe).
• Correct stale behavior claims: consume-filter toggles are registration-time (a disabled filter is never registered); outbox MaxRetries dead-letters via FailedOnUtc; request logging covers only Result-returning requests; the test harness retries a throwing consumer and publishes a captured Fault<T> instead of propagating; inbox retry bounding is per-consumer policy, not a queue MaxRetryCount; entity-id examples use records for value equality.
• Document missing behavior contracts: outbox relay ordering is best-effort with no head-of-line blocking; captured publishes skip later publish filters and the relay bypasses the publish pipeline; poison deliveries (unknown type acked and dropped; undeserializable body nacked to the DLQ when configured, no Fault<T>); IIdempotencyStore context/token semantics; BaseDbContext's unconditional OutboxMessage mapping and the Ignore<OutboxMessage>() opt-out; HTTP mapping response bodies end-to-end (RFC 7807 details, 404/409 problem bodies, typed-union nuance).
• Fill placeholder/empty XML docs (UseMySql on both target frameworks, GetResponseAsync) and fix wrong property docs.
• Give Vulthil.Extensions.Hosting a docs article and Vulthil.Extensions.Testing an accurate identity; complete the package index and getting-started tables (nine packages were unlisted); standardize README links on the documentation site root (the site publishes only versioned slugs, so unversioned deep links 404 and pinned ones rot on pruning) and satellite cross-links on relative in-site links.
• Replace the repo-global nuget tag list (shared-kernel;ddd;cqrs;result-pattern;dotnet on all 24 packages) with per-package tags describing each package's actual contents, and align Vulthil.Extensions.Testing's package description with its real surface.

Verification

• Full solution build clean (TreatWarningsAsErrors), so all XML doc edits compile.
• docfx docs/docfx.json (same invocation as the docs workflow) builds with 0 warnings / 0 errors — all links, anchors, and the new article/toc wiring resolve.
• Diff grepped to confirm no internal tracking identifiers appear in shipped docs.
• dotnet pack spot-check confirms the per-package tags land in the generated nuspec.

Backport to v1.0: no — docs republish with the next release; the main docs slug updates immediately on merge.

[claude]

Code review

No issues found. Checked for bugs and CLAUDE.md compliance.