cmd, replay: filter out the commands before command start time

[YangKeao]

What problem does this PR solve?

Issue Number: close #874

Problem Summary:

What is changed and how it works:

1. Add a new field cmdstarttime in HTTP API.
2. Add a new flag command-start-time in replayer and tiproxyctl cli.
3. Modify the decoder to support filter out commands according to the config.

Check List

Tests

• Unit test
• Integration test
• Manual test (add detailed scripts or steps below)
• No code

Notable changes

• Has configuration change
• Has HTTP API interfaces change
• Has tiproxyctl change
• Other user behavior changes

Release note

Please refer to Release Notes Language Style Guide to write a quality release note.

None

[pingcap-cla-assistant]

All committers have signed the CLA.

[codecov-commenter]

Codecov Report

❌ Patch coverage is 52.72727% with 26 lines in your changes missing coverage. Please review.
⚠️ Please upload report for BASE (main@76929fb). Learn more about missing BASE report.

Files with missing lines	Patch %	Lines
cmd/replayer/main.go	0.00%	9 Missing ⚠️
pkg/server/api/traffic.go	10.00%	8 Missing and 1 partial ⚠️
lib/cli/traffic.go	0.00%	8 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #878   +/-   ##
=======================================
  Coverage        ?   67.35%           
=======================================
  Files           ?      133           
  Lines           ?    12858           
  Branches        ?        0           
=======================================
  Hits            ?     8661           
  Misses          ?     3598           
  Partials        ?      599           

Flag	Coverage Δ
unit	67.35% <52.72%> (?)

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[ti-chi-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: djshow832

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Details

Needs approval from an approver in each of these files:

• OWNERS [djshow832]

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[ti-chi-bot]

[LGTM Timeline notifier]

Timeline:

• 2025-09-14 10:38:40.320526645 +0000 UTC m=+789786.880408141: ☑️ agreed by djshow832.