chore(deploy): config-as-code railway.json + per-service watch path docs

[vivek7405]

Problem

The 4 Railway services in this repo each have a per-subdir watch path. Root-level changes (Dockerfile, root configs) only fire the service whose list happens to mention them. PR #51's Dockerfile fix reached ui-website but not website/docs/blog, which is why webjs.dev/changelog stayed broken even after the merge.

Mapped what each runtime actually depends on (imports, not prose mentions):

Service	Imports from packages/
website	core, cli
docs	core, cli, server
blog (examples/)	core, server
ui-website	core, cli, ui

(ts-plugin is editor-only, no runtime use, so it's intentionally excluded. The docs site mentions @webjskit/ui in prose on the UI doc page but does not import it, so ui is not a runtime dep there.)

Plus everyone is built from the same Dockerfile and runs webjs start, so cli/core/server transitively land in every image.

Fix

Two parts.

1. railway.json at the repo root

Adds a shared, file-controlled record of the build (builder: DOCKERFILE, dockerfilePath: Dockerfile) and the deploy restart policy. watchPatterns is not in this file because a single value at the repo root would apply identically to all four services and the whole point is to make each service trigger on a different set.

2. Per-service watch paths (one-time dashboard cleanup)

For each service: open Settings → Source → Watch Paths, clear the existing list, paste the matching list below, and save.

@webjskit/website (webjs.dev)

/website/**
/changelog/**
/Dockerfile
/package.json
/package-lock.json
/railway.json
/packages/cli/**
/packages/core/**
/packages/server/**

@webjskit/docs (docs.webjs.dev)

/docs/**
/Dockerfile
/package.json
/package-lock.json
/railway.json
/packages/cli/**
/packages/core/**
/packages/server/**

@webjskit-examples/blog (example-blog.webjs.dev)

/examples/blog/**
/Dockerfile
/package.json
/package-lock.json
/railway.json
/packages/cli/**
/packages/core/**
/packages/server/**

@webjskit/ui-website (ui.webjs.dev)

/packages/ui/**
/Dockerfile
/package.json
/package-lock.json
/railway.json
/packages/cli/**
/packages/core/**
/packages/server/**

After the dashboard cleanup

• A change to website/app/page.ts → only the website rebuilds.
• A change to Dockerfile or root package.json → all four rebuild.
• A change to packages/core/** or packages/server/** → all four rebuild (they all run on the framework).
• A change to packages/ui/** → only ui-website rebuilds.
• A change to changelog/<pkg>/<version>.md → only the website rebuilds (the page that reads it).

Test plan

• After dashboard cleanup + this PR merges, push a website-only commit and confirm only the website service rebuilds.
• Push a Dockerfile-only commit and confirm all four rebuild.
• Confirm https://webjs.dev/changelog finally renders the per-package entries (the deferred fix from PR fix(deploy): copy changelog/ into the production image #51).