fix(blueprints): sanitize pagination params to eliminate 501 errors

[vfanucci]

Summary

Root-cause fix for the recurring /blueprints?… 501 errors that have been masked since April via robots.txt Disallow rules.

The page passed page and size query string values raw into the upstream API. Malformed values (size=99999, page=abc, or unexpected tracking params injected by ad networks) caused the API to return 501, which in turn produced a hard render failure on /blueprints rather than a degraded page.

Two protections introduced:

1. Validate and clamp pagination params

   • page: positive integer, capped at 1000 (default 1)
   • size: positive integer, capped at 48 (default 24)
   • Non-numeric or out-of-range values silently fall back to defaults

2. Graceful degradation on API failure

   • Both API calls (tags + blueprint list) are now wrapped in try/catch
   • If the upstream API is unreachable, the page renders the search UI with an empty result set instead of crashing

Also removes the temporary robots.txt workaround:

- # Block the /blueprints pagination bug (critical - 501 errors)
- Disallow: /blueprints?*clid=*
- Disallow: /blueprints?*size=*

The /blueprints listing becomes fully crawlable again with malformed query strings handled defensively at the source.

Context

Identified in the May 13, 2026 SEO follow-up audit (§2.1 and §11.2 — the only remaining Critical-tier item alongside the empty CSP value). The robots.txt workaround was in place since April and has been blocking legitimate crawls for ~30 days.

Test plan

• Local build, then verify the following URLs all return 200 with a rendered page:
  • /blueprints
  • /blueprints?page=1&size=24 (normal)
  • /blueprints?size=99999 (clamped to 48)
  • /blueprints?page=abc&size=-5 (falls back to defaults)
  • /blueprints?clid=fb_test_id (ignored unknown param)
• Verify search and pagination still work normally
• Confirm /robots.txt no longer contains the two /blueprints?* Disallow rules

🤖 Generated with Claude Code

[github-actions]

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## 🔦 Lighthouse Benchmark

Tested: https://ks-seo-blueprints-pagination-501-docs.kestra-io.workers.dev on 2026-05-13 14:33 UTC
No baseline available — scores will appear after the first merge to main

Scores (0–100, higher is better)

Page	Performance	Accessibility	Best Practices	SEO
Home	71	82	59	92
Pricing	96	91	59	100
Enterprise	96	82	59	100
Cloud	89	86	59	100
About Us	99	91	59	100
Docs Landing	81	88	59	92
Contribute to Kestra (simple docs)	91	87	59	92
Flow (full featured docs)	76	90	59	92
Blog Index	63	90	59	100
Blog Post (sample)	88	87	59	100
VS Page (sample)	95	91	59	100
Plugins Landing	86	80	59	92
Plugin Page (sample)	95	87	59	100
Plugin Debug Page (sample)	94	87	59	100
Plugin Debug Return Page (sample)	95	87	59	100
Blueprints Landing	91	80	56	92
Blueprint Audit Logs CSV Export	0	86	0	100

Core Web Vitals (lower is better)

Page	LCP	FCP	TBT	CLS	Speed Index
Home	1.07 s	0.70 s	535 ms	0.002	2.12 s
Pricing	1.10 s	0.53 s	127 ms	0.000	0.81 s
Enterprise	0.98 s	0.53 s	141 ms	0.003	0.81 s
Cloud	2.10 s	0.57 s	93 ms	0.000	0.85 s
About Us	0.80 s	0.58 s	70 ms	0.000	0.96 s
Docs Landing	1.35 s	0.57 s	341 ms	0.000	1.05 s
Contribute to Kestra (simple docs)	1.31 s	0.57 s	195 ms	0.000	0.84 s
Flow (full featured docs)	2.04 s	0.59 s	308 ms	0.002	1.26 s
Blog Index	7.95 s	0.57 s	127 ms	0.000	18.58 s
Blog Post (sample)	2.24 s	0.54 s	95 ms	0.000	0.80 s
VS Page (sample)	1.00 s	0.60 s	148 ms	0.064	0.74 s
Plugins Landing	1.01 s	0.50 s	227 ms	0.000	2.33 s
Plugin Page (sample)	0.94 s	0.56 s	96 ms	0.000	1.84 s
Plugin Debug Page (sample)	0.90 s	0.53 s	140 ms	0.001	1.73 s
Plugin Debug Return Page (sample)	0.97 s	0.50 s	113 ms	0.025	1.67 s
Blueprints Landing	1.51 s	0.75 s	66 ms	0.000	1.83 s
Blueprint Audit Logs CSV Export	0.00 s	0.00 s	0 ms	0.000	0.00 s

Legend

🟢 improved  ·  🔻 regressed  ·  (blank) no significant change
Score threshold: ±10 pts  ·  Metric threshold: ±30% of baseline