zebra-spaces: formalize self-listener as FSM — pure spec + observer-driven side effects + 12 unit tests

Fox 2026-06-04 directive: every system should be a state machine
with unit + integration + functional test coverage. Implicit-state
defects keep biting (kicked-listener-UI-still-green, two-kick race,
cohost-toggle-kills-phone, audio-wedge-no-recovery). Starting the
formalization with the most-broken-today system: self-listener mode.

Spec (selfListenerSpec):
  off ──ENABLE / TOGGLE──▶ on
  on ──DISABLE / TOGGLE / UNMUTE / DEMOTED / CLEAR──▶ off

Sits next to publishSpec, subscribeSpec, callSpec, remoteTileSpec
in zebra-spaces.html. Composed by wireZebraMachines() into
roomMachines.selfListener.

UNMUTE edge encodes fox's invariant: "unmuting should seamlessly
switch them back to the now of the conversation webrtc mesh" — if
the user clicks unmute while on, they implicitly drop back to off.

Side effects (mic mute, streamMode enrolment, remoteAudio muting)
move out of enableSelfListenerMode/disableSelfListenerMode (deleted)
into runSelfListenerEnable / runSelfListenerDisable, called by an
observer attached to the FSM. Pure spec stays Node-testable; the
runtime drives the actual audio plumbing from observed transitions.

Boolean selfListenerMode flag deleted. window.selfListenerMode is
now a getter against the FSM state — single source of truth, no
drift possible. All callers (toggle-button click, mute-unmute,
peer-joined, role-demote, leave) now dispatch FSM events instead
of calling helpers directly.

Tests in test/self-listener-fsm.test.js:
- starts in off
- TOGGLE / ENABLE / DISABLE transitions
- UNMUTE drops to off (the fox-invariant)
- UNMUTE / CLEAR while off is no-op
- DEMOTED drops to off
- CLEAR drops to off
- unknown event refuses
- observer fires on real transitions with prev/state
- runtime observer skips prev===state edges

Existing test/zebra-fsm.test.js updated to extract+expose
selfListenerSpec alongside the other specs (the wireZebraMachines
extract is the integration test).

Makefile gets test-self-listener target + slot in test-all.

All test suites green:
- self-listener:        12 / 12
- zebra-fsm:            83 / 83
- mod-actions:           6 / 6
- web-protocol:       3348 / 3348
- multi-peer-mesh:       8 / 8
- video-track-removal:  18 / 18

Makefile

@@ -53,6 +53,14 @@ test-mesh:
 test-mod-actions:
 	@node test/mod-action-serializer.test.js
 
+# SelfListenerFSM — pins the state-machine contract for the speaker/
+# cohost/host "switch myself to the buffered HTTP listener stream"
+# toggle. Extracts createFSM + selfListenerSpec from the live page so
+# the spec can't drift from shipped transitions (off↔on with
+# TOGGLE/ENABLE/DISABLE/UNMUTE/DEMOTED/CLEAR edges).
+test-self-listener:
+	@node test/self-listener-fsm.test.js
+
 # zebra-spaces JS↔Go protocol parity + vault + ed25519 + (optionally) a live
 # server flow. The live-server tier auto-runs when proxy.unturf.com sits
 # alongside this checkout AND has a Go toolchain — we build the relay binary
@@ -70,7 +78,7 @@ test-zebra-spaces:
 	ZEBRA_SPACES_BINARY=$$bin node test/zebra-spaces.test.js; \
 	rc=$$?; rm -f /tmp/zspc-signal-test; exit $$rc
 
-test-all: test/unit test/integration test/functional test-web test-fsm test-video-removal test-mesh test-mod-actions test-zebra-spaces
+test-all: test/unit test/integration test/functional test-web test-fsm test-video-removal test-mesh test-mod-actions test-self-listener test-zebra-spaces
 	@echo "--- unit ---"
 	@./test/unit
 	@echo "--- integration ---"
@@ -87,6 +95,8 @@ test-all: test/unit test/integration test/functional test-web test-fsm test-vide
 	@node test/multi-peer-mesh.test.js
 	@echo "--- mod-action serializer ---"
 	@node test/mod-action-serializer.test.js
+	@echo "--- self-listener FSM ---"
+	@node test/self-listener-fsm.test.js
 	@echo "--- zebra-spaces ---"
 	@$(MAKE) -s test-zebra-spaces