…from next.config.js (closes #6)

Previously, the App Router RSC entry only handled basePath and trailingSlash.
Redirects, rewrites (beforeFiles/afterFiles/fallback), and custom headers
from next.config.js were completely ignored — both in dev and production.

The config matching logic (pattern matching, redirect/rewrite/header
application) is now embedded inline in the generated RSC entry module,
matching the same order of operations as Next.js.

Also corrects plan.md claim that @vitejs/plugin-rsc supports 'use cache'.

- Bug cloudflare#2: hybrid build skipped Pages Router pre-rendering when App Router entry
  also present — fix: only bail out on pure App Router builds (no pages entry)
- Bug #1: getOutputPath traversal guard bypassed on Windows by backslash urlPath
  — fix: reject urlPath containing backslashes before posix normalize
- Bug cloudflare#4: double-counting in result.skipped when AbortController fires and
  res.text() throws — fix: replace await res.text() with res.body?.cancel()
- Bug cloudflare#6: dynamic routes without getStaticPaths/generateStaticParams classified
  as 'ssr' — fix: use 'unknown' (skipped for unenumerable params, not SSR APIs)
- Bug cloudflare#3: routes that throw in ssrLoadModule silently omitted from
  routeClassifications — fix: wrap in try/catch, add 'unknown' classification
- Bug cloudflare#5: buildReportRows ignored knownRoutes for API routes — fix: check
  known?.get(route.pattern) first, fall back to 'api'
- Bug cloudflare#7: dead !Array.isArray guard after try/catch in expandDynamicAppRoute
  — remove unreachable branch
- Bug cloudflare#8: middlewareHeaders spread onto 200 pre-rendered response could include
  Location header — fix: filter out 'location' before spreading
- Bug cloudflare#9: configOverride typed as Partial<NextConfig> allows unsafe non-scalar
  fields — narrow to Pick<NextConfig, 'output' | 'trailingSlash'>