Fix issue #109: onboard --openrouter-api-key should auto-select OpenRouter provider #320

Job	Run time
Lint	42s
Security Audit	3m 9s
Unit Tests	1m 1s
Check (x86_64-unknown-linux-gnu, default)	2m 52s
Check (aarch64-unknown-linux-gnu, no-default)	3m 56s
Check (aarch64-unknown-linux-gnu, web-tools)	4m 5s
Check (x86_64-unknown-linux-gnu, full)	3m 39s
Check (x86_64-unknown-linux-gnu, no-default)	2m 44s
Check (armv7-unknown-linux-gnueabihf, no-default)	3m 38s
Check (x86_64-apple-darwin, default)	3m 9s
Check (x86_64-pc-windows-msvc, default)	12m 9s
Check (x86_64-pc-windows-msvc, no-default)	10m 35s
Check (aarch64-apple-darwin, default)	2m 56s
E2E Tests	3m 7s
Integration Tests	57s
Build (${{ matrix.target }})	0s
	58m 39s

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