Assemble Remote speech before reader delivery

docs/tentacle-remote-speech.md

@@ -2,7 +2,10 @@
 
 This increment adds typed speech IPC and an explicit reader-owned mailbox. It
 does not connect the speech worker, observe local output, or make Remote speak.
-The external source command remains relay-only. Base reader revision: `4f9b89e`
+The external coordinator now connects this IPC to relay speech; the production
+reader still has no presentation owner or output observer. The current increment
+adds atomic assembly of split incoming utterances before owner admission.
+Original base reader revision: `4f9b89e`
 on `testing`; matching Tentacles base: `0c74038` on `master`, plus the pending
 connection-command changes. No active or installed reader was replaced.
 
@@ -26,13 +29,35 @@ Child `remote.present` takes `RemotePresentation`: lease, epoch, monotonically
 increasing operation sequence and speech. The sequence is shared with heartbeat
 and close. Admission requires a live controller lease with `remote-present`.
 Without a reader owner calling `Session.EnableRemoteSpeech`, it returns `-32601`.
-The queue holds at most 64 items, never blocks the IPC reader, and preserves FIFO
-speech/cancel/pause order. Overflow revokes the entire lease and returns `-32002`;
-it cannot drop a cancel while admitting newer speech. Speech does not refresh
-the heartbeat deadline.
+The queue never blocks the IPC reader and preserves FIFO speech/cancel/pause
+order. Across incomplete assemblies, queued deliveries and work in flight, each
+lease retains at most 64 speech frames and 256 KiB of canonical speech JSON.
+Overflow revokes the entire lease and returns `-32002`; it cannot drop a cancel
+while admitting newer speech. Speech does not refresh the heartbeat deadline.
+
+For split speech, `RemotePresentation` also accepts `utterance` and `final`.
+Omitting both retains the single-call contract. A nonzero utterance identifies
+one assembly and equals the first fragment's operation sequence. Later fragments
+carry that same identifier and a strictly increasing operation sequence; the
+last sets `final: true`. Only speak can be grouped, and every fragment must have
+the same priority. Heartbeats may advance the shared sequence between fragments.
+Only one assembly may be pending; interleaved effects, changed identifiers or
+priorities return `-32602` without committing a prefix or consuming the sequence.
+Replay still returns `-32001`. Null/unknown fields and invalid grouping metadata
+are rejected; both SDKs expose matching presentation validators.
+
+No fragment reaches the owner before the final call succeeds. Finalization
+queues one delivery containing every frame, in order. An unfinished assembly
+stays bounded until completed or its lease ends; it has no independent renewal
+or retry. Revocation, replacement, close, policy cancellation, process loss and
+heartbeat expiry discard it. No relay protocol extension is involved.
 
 The owner receives `RemoteSpeechDelivery` containing a cancellation context,
-lease and validated speech. It must select session shutdown, check the context
+lease, `Speeches` slice and idempotent `Release` callback. The slice is one
+complete effect/utterance; apply priority once, preserving all fragment states
+and boundaries. The owner must call Release after delivery or discard and drop
+its references. Dequeue alone does not return budget; stale releases cannot
+debit a replacement lease. It must select session shutdown, check the context
 and `RemoteContext` at delivery, apply focus/secure-input/speech policy, keep
 remote cancellation separate from local status, and mark remote origins so they
 cannot be observed again. Revocation immediately cancels contexts and drains
@@ -52,18 +77,24 @@ Tentacle must recheck lease/epoch and peer readiness before sending over a relay
 Run from this checkout:
 
 ```sh
-GOCACHE=/tmp/cthulhu-cache GOPROXY=off go test -race ./internal/tentaclewire ./internal/tentacle ./sdk/... -count=1
+GOCACHE=/tmp/cthulhu-cache GOPROXY=off go test -race ./internal/tentaclewire ./internal/tentacle ./sdk/... -count=1 -timeout=240s
 ```
 
 Real Go/Python child processes cover typed speech and observed events, absent
 owners, role/grant denial, replay, ordering, revocation and queue overflow.
-Shared validation cases cover null/type/unknown-field rejection and escaped
-byte bounds. Existing lifecycle/SDK tests exercise old 1.0 behavior, process
-failure, timeout, event overflow and installation contracts.
+Shared validation cases cover null/type/unknown-field rejection, grouping
+metadata and escaped byte bounds. Assembly tests cover no-prefix admission,
+interleaving, replay, priority consistency, heartbeats, in-flight accounting,
+idempotent/stale release, byte/frame overflow and retirement. A private TLS
+fixture in `TestRemoteConnectionCommandPrivateRelay` also passes long escaped
+multilingual speech through the actual source command and reader host to one
+complete test-owner delivery. Existing lifecycle/SDK tests exercise old 1.0
+behavior, process failure, timeout, event overflow and installation contracts.
 
-Next: connect the policy-resolved speech worker and the external coordinator,
-with origin ownership, secure/secret exclusion, delivery-time policy, local
-priority, cancellation generations and atomic treatment of split utterances.
+Next: connect the policy-resolved speech worker with origin ownership,
+secure/secret exclusion, delivery-time policy, local
+priority and cancellation generations. Atomic IPC assembly is implemented;
+it does not establish backend priority/cancel behavior or audible delivery.
 Pause support or cancel-on-pause behavior and NVDA priority fidelity must be
 resolved there. The codec transports metadata without claiming backend behavior.
 Then verify normal reading, key echo, read-all, spelling, speech modes and local