feat(realtime): add support for broadcast replay configuration

[grdsdev]

Summary

• Added ReplayOption type for configuring broadcast replay
• Added replay field to RealtimeChannelBroadcastConfig
• Added BroadcastMeta type for replay metadata
• Added meta field to BroadcastPayload to receive replay information

Changes

This PR implements broadcast replay support following the pattern from realtime-js PR #540:

1. ReplayOption: New TypedDict with since (int) and optional limit (int)
2. RealtimeChannelBroadcastConfig: Added optional replay field
3. BroadcastMeta: New TypedDict with replayed (bool) and id (str)
4. BroadcastPayload: Added optional meta field

Usage

# Configure broadcast with replay
channel = client.channel('my-channel', {
    'config': {
        'broadcast': {
            'self': True,
            'ack': True,
            'replay': {
                'since': 1234567890,
                'limit': 100
            }
        }
    }
})

# Broadcast callback receives meta field
def on_broadcast(payload):
    if payload.get('meta', {}).get('replayed'):
        print(f"Replayed message: {payload['meta']['id']}")

Test plan

• Verify type checking passes
• Test broadcast replay configuration
• Verify meta field is properly typed in callbacks

🤖 Generated with Claude Code

[coveralls]

Pull Request Test Coverage Report for Build 18227834373

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 5 unchanged lines in 1 file lost coverage.
• Overall coverage increased (+0.005%) to 93.876%

---

Files with Coverage Reduction	New Missed Lines	%
src/realtime/types.py	5	95.54%

Totals
Change from base Build 18227491171:	0.005%
Covered Lines:	8722
Relevant Lines:	9291

---

💛 - Coveralls

[o-santi]

I don't think these changes in particular are enough to make it work, because RealtimeChannelBroadcastConfig is not directly sent over wire, but instead read from inside subscribe. I believe you need to read that information inside the function to generate the config_payload correctly.

[grdsdev]

I don't think these changes in particular are enough to make it work, because RealtimeChannelBroadcastConfig is not directly sent over wire, but instead read from inside subscribe. I believe you need to read that information inside the function to generate the config_payload correctly.

@o-santi just wrote a few tests to confirm this, and the config is properly sent over, no need for additional changes, can you review it again?

[o-santi]

I see what is happening. replay is a subfield of broadcast, which is already read from inside subscribe, so it is sent normally by wire. Small nitpick on temp file but should be correct.

[o-santi]

I don't think this file is supposed to exist.