Use local icons URL for test web assets build

[IanCal]

Currently in CI and for local dev we hit the production icons. While this doesn't seem to save much/any time in CI it's about a 20+% speedup locally for me (I assume due to latency hitting the US from the UK, balanced against a http2 server vs local http1.1), and removes a production requirement for CI and dev.

Tests already started the server, we just never used it.

Local dev built things but wasn't setup to start the server

Summary

• Add CORS headers to the local server for icons to be suported
• switch host default iconsURL to http://localhost:4206 for local-first behavior, matching the other defaults
• remove ICONS_URL from test-web-assets and set production ICONS_URL=https://boxel-icons.boxel.ai in build-host env setup
• start icons from realm-server start-development.sh and start-test-realms.sh, and update orchestrator scripts to rely on those scripts while still waiting for http://localhost:4206 readiness

Key things to review

• Is this override enough for the build and deployments to be pointing to the correct place
• Does this correctly work launching locally for development
• Start-all are all as far as I understand just for local work, any of these scripts actually used for staging/prod?

[github-actions]

Preview deployments

• Host staging preview
• Host production preview
• Boxel UI staging preview

[github-actions]

Host Test Results

    1 files  ±0      1 suites  ±0   3h 7m 48s ⏱️ + 1h 21m 26s
1 856 tests +2  1 813 ✅  - 26  14 💤 ±0   0 ❌ ± 0  29 🔥 +28 
1 871 runs  +2  1 799 ✅  - 54  14 💤 ±0  29 ❌ +28  29 🔥 +28 

For more details on these errors, see this check.

Results for commit 7234df4. ± Comparison against base commit e7401f2.

♻️ This comment has been updated with latest results.

[Copilot]

Pull request overview

This PR optimizes local development and CI by switching from production icons URLs to a locally-served icons server, eliminating external dependencies and improving performance (especially for developers outside the US).

Changes:

• Modified default iconsURL configuration to use http://localhost:4206 for local-first behavior
• Added CORS headers to boxel-icons server for authenticated requests (Authorization, X-Boxel-Assume-User)
• Integrated icons server startup into development and test realm scripts with proper lifecycle management
• Set production ICONS_URL=https://boxel-icons.boxel.ai in build-host workflow for deployments
• Updated test expectations to use localhost icons URLs instead of production URLs

Reviewed changes

Copilot reviewed 14 out of 14 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
packages/boxel-icons/package.json	Added specific CORS headers (Authorization, X-Boxel-Assume-User) to serve command for authenticated icon requests
packages/boxel-icons/README.md	Updated documentation to note CORS headers for authenticated fetches
packages/host/config/environment.js	Changed default iconsURL from production to http://localhost:4206
packages/host/tests/integration/realm-indexing-test.gts	Updated test expectations to use localhost:4206 instead of production icons URL
packages/realm-server/scripts/start-icons.sh	New script to start icons server with idempotent behavior (checks if already running)
packages/realm-server/scripts/start-development.sh	Integrated icons server startup with background process management and cleanup
packages/realm-server/scripts/start-test-realms.sh	Integrated icons server startup with background process management and cleanup
packages/realm-server/scripts/start-without-matrix.sh	Added icons URL to readiness check wait conditions
packages/realm-server/scripts/start-all.sh	Added icons URL to readiness check wait conditions
packages/realm-server/scripts/start-all-except-optional.sh	Added icons URL to readiness check wait conditions
packages/realm-server/scripts/start-services-for-matrix-tests.sh	Added icons URL to readiness check wait conditions
packages/realm-server/scripts/start-services-for-host-tests.sh	Added icons URL to readiness check wait conditions
packages/realm-server/package.json	Added start:icons npm script
.github/workflows/build-host.yml	Set ICONS_URL=https://boxel-icons.boxel.ai for production builds

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[habdelra]

looks good, could we also document in the port table of the project readme that we are using 4206 for serving icons?