Add timestamp provenance and precision timing modes

[raphael-solace]

Why: Makes timing output trustworthy by showing whether timestamps came from local receive time, JCSMP, sender metadata, decoded trace payloads, or declared PTP/White Rabbit clock context.

Stack note: Builds on codex/cloudevents-schema-validation.

Implementation notes:

• Default PrettyDump behavior remains unchanged unless the new flags are used.
• This branch is part of the 10-PR QoL series and should be reviewed in order.

Verification:

• JAVA_HOME="$HOME/AnypointCodeBuilder/java/jdk-17.0.13+11/Contents/Home" ./gradlew clean test installDist --no-daemon
• build/staged/bin/prettydump --help