Fix Bulletin allowance slot key handling

[charlesHetterich]

Summary

• request Bulletin allowance during init through the RFC10 resource-allocation flow again
• normalize mobile-returned Bulletin slot-account keys before caching/signing
• verify cached Bulletin allowance against chain state and request an additional allocation when cached allowance exists but quota is insufficient
• keep the Bulletin authorization faucet message as the fallback when the returned account is still not usable on-chain

Testing

• pnpm exec vitest run src/utils/allowances/host.test.ts src/utils/allowances/slotKeys.test.ts src/utils/allowances/bulletin.test.ts src/commands/init/completion.test.ts src/utils/deploy/playground.test.ts
• pnpm format:check
• pnpm lint:license
• pnpm test
• pnpm build

[github-actions]

Dev build ready — try this branch:

curl -fsSL https://raw.githubusercontent.com/paritytech/playground-cli/main/install.sh | VERSION=dev/fix/bulletin-mobile-slot-key-normalization bash

[github-actions]

E2E Test Pass · ✅ PASS

Tag: e2e-ci-pr · Branch: fix/bulletin-mobile-slot-key-normalization · Commit: f87ad9c · Run logs

Cell	Result	Time
pr-deploy-cdm	✅ PASS	3m14s
pr-init-session	✅ PASS	1m41s
pr-install	✅ PASS	1m11s
pr-deploy-foundry	✅ PASS	1m30s
pr-mod	✅ PASS	2m00s
pr-preflight	✅ PASS	1m34s
pr-deploy-frontend	✅ PASS	3m10s
${{ matrix.cell }}	⏭️ SKIP	0m00s
${{ matrix.cell }}	⏭️ SKIP	0m00s

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