v1.0.5 - dashboard upstream compatibility fix

Fixes Home Assistant add-on startup failures caused by fragile dashboard source patching after upstream Hermes dashboard changes.

What changed:

• Moves dashboard source rewriting into a tested helper script instead of multi-expression sed calls.
• Skips source patches for modern Hermes dashboards that already support proxy prefixes via X-Forwarded-Prefix.
• Repairs partially patched v1.0.4 dashboard sources from failed previous starts.
• Keeps legacy fallback patches for older root-path-only Hermes dashboard sources.
• Forwards the dashboard prefix from HA Ingress or custom reverse proxies to Hermes.
• Adds regression tests for modern upstream, legacy fallback, and the sed delimiter failure class.

Thanks to @imcvampire for pinpointing the sed delimiter crash in PR #4.