Update Railpack's support of .NET/C#

[danjrwalsh]

Summary

Railpack has natively supported .NET since Nov 2025, yet Railway's docs are still showing its not supported and requiring the usage of Dockerfile.

• Document Railpack’s built-in .NET support by adding .NET/C# to the supported languages list
• Update the ASP.NET Core guide so GitHub/CLI deploys no longer say a Dockerfile is required, and note *.csproj detection plus automatic ASPNETCORE_URLS / PORT binding
• Keep Dockerfile as an optional path and bump the sample images to .NET 10

Test plan

• Confirm /builds/railpack lists .NET/C# and the Dotnet docs link works
• Confirm /guides/aspnet-core no longer says Railpack lacks .NET support

[rw-growth-check]

Growth check — AMH estimate

#1289 @ de4cbf1 — advisory only. Judgment ranges, ≤2 significant figures; SEO and AEO legs are never summed (AMH_RULES v2.2, constants v2.3 (2026-08-06)).

Files considered:

• content/docs/builds/railpack.md (modified)
• content/guides/aspnet-core.md (modified)

SEO leg (Google surface)

no estimate (see caveats)

AEO leg (AI assistants)

5.7–17 visits/mo

Gates

• SERP page type(s): unknown
• AI Overview present: absent
• Gated to zero: no
• Gauge topic: docker-container-hosting (matched)

Keyword candidates for the AMH panel

None found for this content.

Caveats & verification stamps

• Subject may also span sibling topic(s): serverless-function-deployment, media-and-streaming-server-deployment, remote-mcp-server-hosting — the AEO leg prices ONE topic; verify subject-matched prompts (gauge_get_prompt_answers) before summing sibling shares (AMH_RULES §3.10/§4).
• Current-traffic baseline (modified pages): /builds/railpack: 274 pageviews, 233 visitors (2 AI-referred) over ~2mo; /railpack: 2 pageviews, 2 visitors (0 AI-referred) over ~2mo; /guides/aspnet-core: 103 pageviews, 95 visitors (3 AI-referred) over ~2mo.
• Verification pass: PostHog rates are stamped person- vs event-level — visitors are person-level (uniqExact person_id), pageviews are event-level (AMH_RULES §5/§8).
• SERP page-type gate could not be evaluated (no SERP page-type data) — verify winnability manually before pricing (AMH_RULES §2.2).
• SEO leg: no on-subject keyword volumes found — no estimate (derive seeds manually and re-check).
• Verification pass: the AEO Δ is a labeled ASSUMPTION (+1pt; caps +2 pts/quarter, +6 pts/12mo — AMH_RULES §3.5).

How to go deeper

Ask an agent with the railway-internal MCP (the gauge_* / ahrefs_* / posthog_* tools) or the amh-growth skill for observed-anchor pricing, live SERP inspection, topic curation, and citation checks.

Ahrefs cost: 200 API units · How AMH is calculated