SP2: reconcile SyncPlay flat wire frame-shape

[detain]

SP2: SyncPlay frame-shape reconciliation

Problem

• Inbound: MessageHandler::handle() extracts ['data'] — flat frames have NO data key, so all fields are lost
• Outbound: Connection::sendMessage() wraps syncplay payloads under data (deprecated Tizen envelope)
• sendError() emits code while Messages::error() uses error_code

Fix

Inbound: Pass the whole flat message as payload for syncplay types; keep tolerant unwrap for deprecated {type,data} envelope (dashboard path unchanged)

Outbound: Build every syncplay frame with Messages::* factories and send flat via new Connection::sendFlat()

GROUP_STATE: Emit {group:{...}, your_id} flat at top level (not under data)

Error: Align sendError() to emit error_code

Files changed

• src/Server/WebSocket/MessageHandler.php — flat dispatch + protocol_version validation
• src/Server/WebSocket/Connection.php — sendFlat() method
• src/Server/WebSocket/ConnectionInterface.php — sendFlat() in contract
• src/Session/SyncPlay/SyncPlayManager.php — error_code alignment + flat GROUP_STATE
• New tests: MessageHandlerFrameShapeTest.php, MessagesFrameShapeTest.php

Verification

• ./vendor/bin/phpunit — 143 tests, 412 assertions ✅
• ./vendor/bin/phpstan analyze --level=9 — no errors ✅
• ./vendor/bin/phpcs PSR-12 — no errors ✅

Dependency

Pairs with @phlix/syncplay Phase 8 (wire-shape checkpoint)

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[codacy-production]

Not up to standards ⛔

🔴 Issues 16 medium · 81 minor

Alerts:
⚠ 97 issues (≤ 0 issues of at least minor severity)

Results:
97 new issues

Category	Results
UnusedCode	2 medium
BestPractice	12 medium
Documentation	27 minor
ErrorProne	2 medium
CodeStyle	54 minor

View in Codacy

🟢 Metrics 24 complexity · 0 duplication

Metric	Results
Complexity	24
Duplication	0

View in Codacy

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