fix: replace panic-based error handling with recoverable error paths

[Ishita-190]

Fixes: #41
Files changed:

• apps/mofa-asr/src/screen/mod.rs,
• node-hub/dora-funasr-nano-mlx/src/main.rs
• mofa-dora-bridge/src/parser.rs
• node-hub/dora-gpt-sovits-mlx/src/ssml.rs

Changes made:

• Startup logic that previously unwrapped optional engine state now handles missing state gracefully.
• Replaced expect("... mutex poisoned") with recovery logic using into_inner() so the UI can continue operating even if a mutex becomes poisoned after a prior failure.
• Parsing paths no longer rely on runtime unwrap() calls. Failures now return clearer errors instead of panicking during execution.
• Test assertions that previously used raw unwrap() now use expect() with descriptive messages to improve debugging when failures occur.

All changes are working as expected.

[Ishita-190]

@BH3GEI please take a look!