Add startTimestamp to context dev console

[davsclaus]

Summary

• Adds startTimestamp (epoch millis) to the context dev console JSON output, using CamelContext.getClock().get(ContextEvents.START).getCreated()
• Adds Started: line to the text output showing the context start date
• Uses the existing Clock API — no new APIs needed

Test plan

• Compiles
• CI green

🤖 Generated with Claude Code

[github-actions]

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[github-actions]

🧪 CI tested the following changed modules:

• core/camel-console

All tested modules (13 modules)

• Camel :: All Core Sync point
• Camel :: Console
• Camel :: DSL :: CLI Connector
• Camel :: DSL :: CLI Debug
• Camel :: Diagram
• Camel :: JBang :: Console
• Camel :: JBang :: MCP
• Camel :: JBang :: Plugin :: Route Parser
• Camel :: JBang :: Plugin :: TUI
• Camel :: JBang :: Plugin :: Validate
• Camel :: Launcher :: Container
• Camel :: YAML DSL :: Validator
• Camel :: YAML DSL :: Validator Maven Plugin

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[gnodet]

Clean, small change adding startTimestamp to the context dev console output. Uses ContextEvents.START clock for both text mode (human-readable date) and JSON mode (epoch millis). Null-safe with the if (startClock != null) guard. Preserves the existing uptime field.

LGTM.

Fully automatic review from Claude Code