Blueprints: Add base64 deeplink blueprint handling (exploration)

[ivan-ottinger]

ℹ️ This is an exploratory PR, not meant to be merged.

Related issues

Related to STU-921
Related discussion: p1761669460264369/1761647123.631989-slack-C04GESRBWKW

Proposed Changes

• add base64 deeplink handling

Testing Instructions

Example deeplink to test with:

wpcom-local-dev://add-site?blueprint=eyJwcmVmZXJyZWRWZXJzaW9ucyI6eyJwaHAiOiI4LjMiLCJ3cCI6ImxhdGVzdCJ9LCJzdGVwcyI6W3sic3RlcCI6Imluc3RhbGxUaGVtZSIsInRoZW1lRGF0YSI6eyJyZXNvdXJjZSI6IndvcmRwcmVzcy5vcmcvdGhlbWVzIiwic2x1ZyI6ImFzdHJhIn0sIm9wdGlvbnMiOnsiYWN0aXZhdGUiOnRydWV9fSx7InN0ZXAiOiJpbnN0YWxsUGx1Z2luIiwicGx1Z2luRGF0YSI6eyJyZXNvdXJjZSI6IndvcmRwcmVzcy5vcmcvcGx1Z2lucyIsInNsdWciOiJ3b3JkcHJlc3Mtc2VvIn0sIm9wdGlvbnMiOnsiYWN0aXZhdGUiOnRydWV9fV19

Pre-merge Checklist

• Have you checked for TypeScript, React or other console errors?

[github-actions]

📊 Performance Test Results

Comparing faa11a0 vs trunk

site-editor

Metric	trunk	faa11a0	Diff	Change
load	10271.00 ms	10386.00 ms	+115.00 ms	🔴 1.1%

site-startup

Metric	trunk	faa11a0	Diff	Change
siteCreation	14540.00 ms	13976.00 ms	-564.00 ms	🟢 -3.9%
siteStartup	3942.00 ms	3952.00 ms	+10.00 ms	🔴 0.3%

---

Results are median values from multiple test runs.

Legend: 🟢 Improvement (faster) | 🔴 Regression (slower) | ⚪ No change

[gavande1]

Not related to this PR, but in general, it just occurred to me at this point, we might want to reconsider the deeplink URL prefix wpcom-local-dev://. Perhaps something like wp-studio-local-dev:// or simply wp-studio-dev:// would be more appropriate. While Studio is offered by WordPress.com, our goal is for it to become the go-to tool for WordPress development, not just for WordPress.com users. The platform-specific advantages can come later, but the core identity should feel broader and more inclusive from the start.

[ivan-ottinger]

Not related to this PR, but in general, it just occurred to me at this point, we might want to reconsider the deeplink URL prefix wpcom-local-dev://. Perhaps something like wp-studio-local-dev:// or simply wp-studio-dev:// would be more appropriate. While Studio is offered by WordPress.com, our goal is for it to become the go-to tool for WordPress development, not just for WordPress.com users. The platform-specific advantages can come later, but the core identity should feel broader and more inclusive from the start.

I have created a separate task (STU-936) where we can take a closer look at the renaming. 🙂

[ivan-ottinger]

Closing in favor of #2042.