Fix public GitHub analysis without hosted session config

[alihd-tech]

Fix

Public username reports were still initializing the strict hosted session helper inside /api/analyze?username=....

In production, a deployment without SESSION_SECRET could therefore render the public profile header successfully but fail the client-side analysis request before GitHub analysis began.

Changes

• public username analysis now uses the optional session helper
• private signed-in dashboard keeps strict session enforcement
• session/token reuse still happens only when the visitor is analyzing their own account
• the entire analysis handler is inside the error boundary
• the dashboard now surfaces HTTP/server details instead of collapsing non-JSON failures into Unknown error

No private-token behavior or analytics calculation is changed.

[vercel]

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Resource is limited - try again in 24 hours (more than 100, code: "api-deployments-free-per-day").

Learn More: https://vercel.com/alihdtechs-projects?upgradeToPro=build-rate-limit