♻️ move telemetry to pre-start step

[mormubis]

Motivation

Starting telemetry collection earlier in the SDK lifecycle enables:

• Capture of initialization-phase events
• Better error tracking during bootstrap
• Reduced circular dependencies through two-phase initialization

Changes

• Split telemetry into collection phase (preStart) and transport phase (startLogs/startRum)
• Hooks start as empty registry in preStart, populated later during startLogs/startRum
  Telemetry interface now includes startTransport() method for deferred initialization
• Backward compatible: existing code continues to work unchanged

Test instructions

Checklist

• Tested locally
• Tested on staging
• Added unit tests for this change.
• Added e2e/integration tests for this change.

[cit-pr-commenter-54b7da]

Bundles Sizes Evolution

📦 Bundle Name	Base Size	Local Size	𝚫	𝚫%	Status
Rum	167.75 KiB	168.28 KiB	+546 B	+0.32%	✅
Rum Profiler	4.33 KiB	4.33 KiB	0 B	0.00%	✅
Rum Recorder	24.48 KiB	24.48 KiB	0 B	0.00%	✅
Logs	56.25 KiB	56.79 KiB	+554 B	+0.96%	✅
Flagging	944 B	944 B	0 B	0.00%	✅
Rum Slim	124.85 KiB	125.39 KiB	+556 B	+0.43%	✅
Worker	23.63 KiB	23.63 KiB	0 B	0.00%	✅

🚀 CPU Performance

Action Name	Base CPU Time (ms)	Local CPU Time (ms)	𝚫%
addglobalcontext	N/A	0.0042	N/A
addaction	N/A	0.0202	N/A
adderror	N/A	0.0186	N/A
addtiming	N/A	0.0031	N/A
startview	N/A	0.0039	N/A
startstopsessionreplayrecording	N/A	0.001	N/A
logmessage	N/A	0.0236	N/A

🧠 Memory Performance

Action Name	Base Memory Consumption	Local Memory Consumption	𝚫
addglobalcontext	N/A	26.35 KiB	N/A
addaction	N/A	114.70 KiB	N/A
addtiming	N/A	26.51 KiB	N/A
adderror	N/A	116.71 KiB	N/A
startstopsessionreplayrecording	N/A	26.36 KiB	N/A
startview	N/A	487.03 KiB	N/A
logmessage	N/A	46.07 KiB	N/A

🔗 RealWorld

[datadog-official]

✅ Tests

🎉 All green!

❄️ No new flaky tests detected
🧪 All tests passed

🎯 Code Coverage
• Patch Coverage: 79.31%
• Overall Coverage: 77.32% (-0.01%)

View detailed report

_{This comment will be updated automatically if new data arrives.
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