Fix decrypted payload hexview

[maebli]

Summary:

• Make hexview key-aware so decrypted payload bytes can be rendered in the docs hex viewer.
• Return decrypted display bytes with record-level annotations for hexview while keeping plain annotated output as the existing segment array.
• Update the docs renderer to use hexview responses directly and render decrypted display bytes when present.
• Rebuild the checked-in docs WASM bundle.

Sample verified:

• Data: 2E44931578563412330333637A2A0020255923C95AAA26D1B2E7493BC2AD013EC4A6F6D3529B520EDFF0EA6DEFC955B29D6D69EBF3EC8A
• Key: 0102030405060708090A0B0C0D0E0F11
• Hexview returns decrypted display bytes and data payloads 2850427, Every/May/25 23:50:00, and 0 with no EncryptedPayload segment.

Validation:

• cargo fmt -- --check
• cargo test --verbose
• cargo test --verbose -F std
• cargo test --verbose -F std,decryption
• cargo clippy -- -D warnings
• cargo clippy -F std,decryption -- -D warnings
• WASM cargo test --verbose
• WASM cargo clippy -- -D warnings
• wasm-pack build --target web
• Node smoke test against docs/m_bus_parser_wasm_pack.js for the provided encrypted frame/key