Default naive seek datetimes to system timezone for RTSP/HTTP catchup

[Copilot]

playseek/catchup requests without an explicit client timezone were being parsed as UTC. On non-UTC deployments this caused recent local-time seeks to miss the RTSP Range: clock= path and fall back to upstream query passthrough.

• Timezone fallback semantics

  • Change naive seek datetime parsing (yyyyMMddHHmmss, naive ISO 8601) to default to the daemon's system timezone when the client does not provide a timezone via User-Agent.
  • Keep explicit-timezone inputs unchanged:
    • Unix timestamps
    • yyyyMMddHHmmssGMT
    • ISO 8601 with Z or ±HH:MM

• RTSP recent-seek behavior

  • Recent local-time playseek values now resolve to the correct UTC instant before the < 1 hour check.
  • This restores the intended RTSP behavior:
    • strip recent seek params from the upstream RTSP URL
    • send PLAY Range: clock=<utc>-

• Shared seek conversion path

  • Apply the same fallback to the shared HTTP/RTSP seek conversion logic so upstream HTTP proxy requests also convert naive local datetimes consistently.

• E2E coverage

  • Add a reproducer for the original failure: daemon running under a non-UTC system timezone, client omits timezone, recent playseek should still trigger RTSP Range: clock=.
  • Add adjacent HTTP coverage for the same naive-datetime conversion path.
  • Isolate timezone-sensitive tests by passing TZ only to the child rtp2httpd process.

• Docs

  • Update the Chinese time-processing guide to document system-timezone fallback for naive datetimes when the client does not send timezone information.

Example of the corrected behavior:

# client request (no TZ in User-Agent, naive local datetime input)
GET /.../catchup?playseek=20260323183140-20260323183835

# before on non-UTC systems
DESCRIBE rtsp://upstream/...?...&playseek=20260323183140-20260323183835
PLAY ...                       # no Range: clock

# after
DESCRIBE rtsp://upstream/...   # recent seek stripped from RTSP URL
PLAY ...
Range: clock=20260323T103140Z-

Original prompt

---

This section details on the original issue you should resolve

<issue_title>v3.12.0-alpha.1 无法触发 Range: clock</issue_title>
<issue_description>网页端测试一小时内回看，不知为何日志里没看见有走 clock 分支，回看正常。

18:38:45 INFO [Worker 0] New client 192.168.96.100:15699 requested URL: /%E5%A4%AE%E8%A7%86/CCTV-5%E4%BD%93%E8%82%B2/catchup?playseek=20260323183140-20260323183835 (method: GET)
18:38:45 INFO [Worker 0] Service matched: 央视/CCTV-5体育/catchup
18:38:45 DEBUG [Worker 0] Creating RTSP service with merged URL: rtsp://10.255.4.140/PLTV/88888888/224/3221225726/10000100000000060000000000247037_0.smil?rrsip=10.255.13.139&zoneoffset=480&icpid=-1&limitflux=-1&limitdur=-1&tenantId=8601&GuardEncType=2&accountinfo=********&playseek=20260323183140-20260323183835&r2h-seek-name=playseek
18:38:45 DEBUG [Worker 0] Found r2h-seek-name parameter: playseek
18:38:45 DEBUG [Worker 0] Using explicitly specified seek parameter name: playseek
18:38:45 DEBUG [Worker 0] Found valid playseek parameter: 20260323183140-20260323183835
18:38:45 DEBUG [Worker 0] Parsed RTSP URL: rtsp://10.255.4.140/PLTV/88888888/224/3221225726/10000100000000060000000000247037_0.smil?rrsip=10.255.13.139&zoneoffset=480&icpid=-1&limitflux=-1&limitdur=-1&tenantId=8601&GuardEncType=2&accountinfo=********
18:38:45 DEBUG [Worker 0] Parsed playseek parameter: 20260323183140-20260323183835
18:38:45 DEBUG [Worker 0] Timezone: No TZ marker in User-Agent
18:38:45 DEBUG [Worker 0] Parsed seek - begin='20260323183140', end='20260323183835'
18:38:45 DEBUG [Worker 0] Timezone: yyyyMMddHHmmss '20260323183140' (TZ offset 0) + seek offset 0 = '20260323183140'
18:38:45 DEBUG [Worker 0] Converted begin time '20260323183140' to UTC '20260323183140'
18:38:45 DEBUG [Worker 0] Timezone: yyyyMMddHHmmss '20260323183835' (TZ offset 0) + seek offset 0 = '20260323183835'
18:38:45 DEBUG [Worker 0] Converted end time '20260323183835' to UTC '20260323183835'
18:38:45 DEBUG [Worker 0] UTC seek parameter: '20260323183140-20260323183835'
18:38:45 DEBUG [Worker 0] RTSP: Parsed URL - host=10.255.4.140, port=554, path=/PLTV/88888888/224/3221225726/10000100000000060000000000247037_0.smil?rrsip=10.255.13.139&zoneoffset=480&icpid=-1&limitflux=-1&limitdur=-1&tenantId=8601&GuardEncType=2&accountinfo=********&playseek=20260323183140-20260323183835
18:38:45 DEBUG [Worker 0] RTSP: Connection to 10.255.4.140:554 in progress (async)
18:38:45 DEBUG [Worker 0] RTSP: Socket registered with poller for connection completion
18:38:45 DEBUG [Worker 0] RTSP: Async connection initiated, state=1
18:38:45 INFO [Worker 0] RTSP: Connected to 10.255.4.140:554
18:38:45 DEBUG [Worker 0] RTSP: Connection to 10.255.4.140:554 completed successfully
18:38:45 DEBUG [Worker 0] RTSP: Prepared request:
OPTIONS rtsp://10.255.4.140/PLTV/88888888/224/3221225726/10000100000000060000000000247037_0.smil?rrsip=10.255.13.139&zoneoffset=480&icpid=-1&limitflux=-1&limitdur=-1&tenantId=8601&GuardEncType=2&accountinfo=********&playseek=20260323183140-20260323183835 RTSP/1.0
CSeq: 1
User-Agent: CTC RTSP 1.0

18:38:45 DEBUG [Worker 0] RTSP: Request sent completely (462 bytes)
18:38:45 DEBUG [Worker 0] RTSP: Request sent completely, waiting for response
18:38:45 DEBUG [Worker 0] RTSP: Server supports GET_PARAMETER for keepalive
18:38:45 DEBUG [Worker 0] RTSP: Server advertised methods: DESCRIBE, SETUP, PLAY, PAUSE, TEARDOWN, SET_PARAMETER, GET_PARAMETER, OPTIONS
18:38:45 DEBUG [Worker 0] RTSP: Received complete header:
RTSP/1.0 200 OK
Public: DESCRIBE, SETUP, PLAY, PAUSE, TEARDOWN, SET_PARAMETER, GET_PARAMETER, OPTIONS
Date: Mon, 23 Mar 2026 10:38:45 GMT
CSeq: 1
Server: HWServer/1.0.0.1

18:38:45 DEBUG [Worker 0] RTSP: Prepared request:
DESCRIBE rtsp://10.255.4.140/PLTV/88888888/224/3221225726/10000100000000060000000000247037_0.smil?rrsip=10.255.13.139&zoneoffset=480&icpid=-1&limitflux=-1&limitdur=-1&tenantId=8601&GuardEncType=2&accountinfo=********&playseek=20260323183140-20260323183835 RTSP/1.0
CSeq: 2
User-Agent: CTC RTSP 1.0
Accept: application/sdp

18:38:45 DEBUG [Worker 0] RTSP: Request sent completely (488 bytes)
18:38:45 DEBUG [Worker 0] RTSP: Request sent completely, waiting for response
18:38:45 DEBUG [Worker 0] RTSP: Received redirect response 302
18:38:45 DEBUG [Worker 0] RTSP: Handling redirect to: rtsp://10.255.9.151:554/PLTV/88888888/224/3221225726/10000100000000060000000000247037_0.smil?rrsip=10.255.13.139&zoneoffset=480&icpid=-1&limitflux=-1&limitdur=-1&tenantId=8601&GuardEncType=2&accountinfo=********&playseek=20260323183140-20260323183835&from=3&hms_devid=492&online=1774262325
18:38:45 DEBUG [Worker 0] RTSP: Parsed URL - host=10.255.9.151, port=554, path=/PLTV/88888888/224/3221225726/10000100000000060000000000247037_0.smil?rrsip=10.255.13.139&zoneoffset=480&icpid=-1&limitflux=-1&limitdur=-1&tenantId=8601&GuardEncType=2&accountinfo=********&playseek=20260323183140-20260323183835&from=3&hms_devid=492&online=1774262325
18:38:45 DEBUG [Worker 0] RTSP: Connection to 10.255.9.151:554 in progress (async)
18:38:45 DEBUG [Worker 0] RTSP: Sock...

</details>



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- Fixes stackia/rtp2httpd#424

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