Make Live Debugger per-second budgets configurable

[watson]

Motivation

Allow Live Debugger users to tune per-second backpressure limits without changing the runtime defaults.

Changes

Add new DD_DEBUGGER.init() options to configure:

• the global snapshot per-second budget
• the default snapshot per-probe per-second budget
• the default non-snapshot per-probe per-second budget

Wire those options into the debugger probe budget logic and reset them when the debugger transport is reset. Add unit tests covering the configurable global snapshot limit and configurable per-probe snapshot/non-snapshot limits.

Test instructions

1. Run yarn test:unit --spec packages/debugger/src/domain/api.spec.ts
2. Run yarn test:unit --spec packages/debugger/src/domain/probes.spec.ts
3. In packages/debugger/src/entries/main.ts, verify that DebuggerInitConfiguration exposes:
   • maxSnapshotsPerSecondGlobally
   • maxSnapshotsPerSecondPerProbe
   • maxNonSnapshotsPerSecondPerProbe
4. In packages/debugger/src/domain/probes.ts, verify those values are used as the runtime defaults when probe-specific sampling is not set.

Checklist

• Tested locally
• Tested on staging
• Added unit tests for this change.
• Added e2e/integration tests for this change.
• Updated documentation and/or relevant AGENTS.md file

[watson]

Warning

This pull request is not mergeable via GitHub because a downstack PR is open. Once all requirements are satisfied, merge this PR as a stack on Graphite.
Learn more

• Add Live Debugger lifetime event budgets #4510
• Make Live Debugger per-second budgets configurable #4509 👈 (View in Graphite)
• Add Live Debugger package #4449 : 5 other dependent PRs (#4480 , #4503 , #4508 and 2 others)
• Fix TanStack Router lint resolution in test app #4513
• main

This stack of pull requests is managed by Graphite. Learn more about stacking.

[cit-pr-commenter-54b7da]

Bundles Sizes Evolution

📦 Bundle Name	Base Size	Local Size	𝚫	𝚫%	Status
Rum	179.42 KiB	179.42 KiB	0 B	0.00%	✅
Rum Profiler	6.16 KiB	6.16 KiB	0 B	0.00%	✅
Rum Recorder	27.03 KiB	27.03 KiB	0 B	0.00%	✅
Logs	56.80 KiB	56.80 KiB	0 B	0.00%	✅
Rum Slim	135.26 KiB	135.26 KiB	0 B	0.00%	✅
Worker	23.63 KiB	23.63 KiB	0 B	0.00%	✅

🚀 CPU Performance

Action Name	Base CPU Time (ms)	Local CPU Time (ms)	𝚫%
RUM - add global context	0.00545	0.0039	-28.44%
RUM - add action	0.0161	0.013	-19.25%
RUM - add error	0.013999999999999999	0.0121	-13.57%
RUM - add timing	0.00295	0.0025	-15.25%
RUM - start view	0.01405	0.0118	-16.01%
RUM - start/stop session replay recording	0.0009	0.0007	-22.22%
Logs - log message	0.016900000000000002	0.0141	-16.57%

🧠 Memory Performance

Action Name	Base Memory Consumption	Local Memory Consumption	𝚫
RUM - add global context	31.53 KiB	32.37 KiB	+859 B
RUM - add action	101.84 KiB	116.65 KiB	+14.80 KiB
RUM - add timing	32.46 KiB	32.04 KiB	-431 B
RUM - add error	104.34 KiB	96.70 KiB	-7.64 KiB
RUM - start/stop session replay recording	32.01 KiB	31.45 KiB	-563 B
RUM - start view	489.22 KiB	497.90 KiB	+8.69 KiB
Logs - log message	99.21 KiB	99.16 KiB	-48 B

🔗 RealWorld

[datadog-datadog-prod-us1]

🎉 All green!

❄️ No new flaky tests detected
🧪 All tests passed

🎯 Code Coverage (details)
• Patch Coverage: 80.00%
• Overall Coverage: 76.68% (-0.02%)

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