Enforce source/destination limit for custom routes

[ijjk]

This ensures we enforce a limit for source/destination values on rewrites, redirects, and headers since these being too long can affect routing performance.

Closes: #27696

[ijjk]

Stats from current PR

Default Build (Decrease detected ✓)

General Overall increase ⚠️

	vercel/next.js canary	ijjk/next.js add/route-size-check	Change
buildDuration	13s	12.7s	-262ms
buildDurationCached	3s	2.9s	-92ms
nodeModulesSize	50 MB	50.1 MB	⚠️ +2.69 kB

Page Load Tests Overall decrease ⚠️

	vercel/next.js canary	ijjk/next.js add/route-size-check	Change
/ failed reqs	0	0	✓
/ total time (seconds)	2.217	2.238	⚠️ +0.02
/ avg req/sec	1127.82	1117.29	⚠️ -10.53
/error-in-render failed reqs	0	0	✓
/error-in-render total time (seconds)	1.227	1.239	⚠️ +0.01
/error-in-render avg req/sec	2037.56	2016.99	⚠️ -20.57

Client Bundles (main, webpack, commons)

	vercel/next.js canary	ijjk/next.js add/route-size-check	Change
745.HASH.js gzip	179 B	179 B	✓
framework-HASH.js gzip	42.2 kB	42.2 kB	✓
main-HASH.js gzip	22.8 kB	22.8 kB	✓
webpack-HASH.js gzip	1.5 kB	1.5 kB	✓
Overall change	66.7 kB	66.7 kB	✓

Legacy Client Bundles (polyfills)

	vercel/next.js canary	ijjk/next.js add/route-size-check	Change
polyfills-HASH.js gzip	31.1 kB	31.1 kB	✓
Overall change	31.1 kB	31.1 kB	✓

Client Pages

	vercel/next.js canary	ijjk/next.js add/route-size-check	Change
_app-HASH.js gzip	980 B	980 B	✓
_error-HASH.js gzip	194 B	194 B	✓
amp-HASH.js gzip	312 B	312 B	✓
css-HASH.js gzip	329 B	329 B	✓
dynamic-HASH.js gzip	2.52 kB	2.52 kB	✓
head-HASH.js gzip	350 B	350 B	✓
hooks-HASH.js gzip	903 B	903 B	✓
image-HASH.js gzip	4.1 kB	4.1 kB	✓
index-HASH.js gzip	261 B	261 B	✓
link-HASH.js gzip	1.66 kB	1.66 kB	✓
routerDirect..HASH.js gzip	319 B	319 B	✓
script-HASH.js gzip	387 B	387 B	✓
withRouter-HASH.js gzip	320 B	320 B	✓
bb14e60e810b..30f.css gzip	125 B	125 B	✓
Overall change	12.8 kB	12.8 kB	✓

Client Build Manifests

	vercel/next.js canary	ijjk/next.js add/route-size-check	Change
_buildManifest.js gzip	490 B	490 B	✓
Overall change	490 B	490 B	✓

Rendered Page Sizes

	vercel/next.js canary	ijjk/next.js add/route-size-check	Change
index.html gzip	530 B	530 B	✓
link.html gzip	542 B	542 B	✓
withRouter.html gzip	524 B	524 B	✓
Overall change	1.6 kB	1.6 kB	✓

---

Webpack 4 Mode (Decrease detected ✓)

General Overall increase ⚠️

	vercel/next.js canary	ijjk/next.js add/route-size-check	Change
buildDuration	10.4s	10.3s	-34ms
buildDurationCached	4s	4s	-5ms
nodeModulesSize	50 MB	50.1 MB	⚠️ +2.69 kB

Page Load Tests Overall decrease ⚠️

	vercel/next.js canary	ijjk/next.js add/route-size-check	Change
/ failed reqs	0	0	✓
/ total time (seconds)	2.247	2.251	0
/ avg req/sec	1112.83	1110.6	⚠️ -2.23
/error-in-render failed reqs	0	0	✓
/error-in-render total time (seconds)	1.218	1.26	⚠️ +0.04
/error-in-render avg req/sec	2052.95	1984.31	⚠️ -68.64

Client Bundles (main, webpack, commons)

	vercel/next.js canary	ijjk/next.js add/route-size-check	Change
17.HASH.js gzip	185 B	185 B	✓
677f882d2ed8..HASH.js gzip	13.8 kB	13.8 kB	✓
framework.HASH.js gzip	41.9 kB	41.9 kB	✓
main-HASH.js gzip	10.6 kB	10.6 kB	✓
webpack-HASH.js gzip	1.19 kB	1.19 kB	✓
Overall change	67.7 kB	67.7 kB	✓

Legacy Client Bundles (polyfills)

	vercel/next.js canary	ijjk/next.js add/route-size-check	Change
polyfills-HASH.js gzip	31.3 kB	31.3 kB	✓
Overall change	31.3 kB	31.3 kB	✓

Client Pages

	vercel/next.js canary	ijjk/next.js add/route-size-check	Change
_app-HASH.js gzip	965 B	965 B	✓
_error-HASH.js gzip	3.74 kB	3.74 kB	✓
amp-HASH.js gzip	552 B	552 B	✓
css-HASH.js gzip	333 B	333 B	✓
dynamic-HASH.js gzip	2.71 kB	2.71 kB	✓
head-HASH.js gzip	2.97 kB	2.97 kB	✓
hooks-HASH.js gzip	911 B	911 B	✓
index-HASH.js gzip	231 B	231 B	✓
link-HASH.js gzip	1.64 kB	1.64 kB	✓
routerDirect..HASH.js gzip	298 B	298 B	✓
script-HASH.js gzip	2.94 kB	2.94 kB	✓
withRouter-HASH.js gzip	294 B	294 B	✓
e025d2764813..52f.css gzip	125 B	125 B	✓
Overall change	17.7 kB	17.7 kB	✓

Client Build Manifests

	vercel/next.js canary	ijjk/next.js add/route-size-check	Change
_buildManifest.js gzip	499 B	499 B	✓
Overall change	499 B	499 B	✓

Rendered Page Sizes

	vercel/next.js canary	ijjk/next.js add/route-size-check	Change
index.html gzip	578 B	578 B	✓
link.html gzip	591 B	591 B	✓
withRouter.html gzip	571 B	571 B	✓
Overall change	1.74 kB	1.74 kB	✓

Commit: c6ac908