State machines: several named transitions between the same pair of states, repeated self transitions as rings; check total 1092 (#162)

Development.md

@@ -12,7 +12,7 @@ npm run check        # typecheck + lint + format:check + tests, the gate CI runs
                      #   code is lost (tail's is reported), so a red run reads as green
 npm run build        # writes dist/ and regenerates index.html
 ./build.sh           # the same under `set -o pipefail`, for callers that pipe the output
-node tools/seed-e2e.mjs && node tools/e2e.mjs                 # 1088 editor checks, screenshots in /tmp/gm-e2e-*.png
+node tools/seed-e2e.mjs && node tools/e2e.mjs                 # 1092 editor checks, screenshots in /tmp/gm-e2e-*.png
 GM_STEPS=20 node tools/e2e.mjs                                # or 1-12, or 6,20 — a subset while working on one step
 ./e2e.sh start [GM_STEPS]                                     # the same run detached, see below
 ./e2e.sh status                                               # live progress, or the last run's result

State-machines.md

@@ -28,14 +28,21 @@ therefore still *carries* an `in` and an `out` port — a port is the only ancho
 editor — the editor simply never draws them and never lets them be grabbed. Between two states the
 edge is a **straight arrow** rather than the usual curve, running border to border with a little
 air at each end. Two transitions between the same pair are pushed apart, so a there-and-back pair
-lies side by side instead of on top of each other. Two arrows the *same* way round are refused
-(`Already connected`), because every transition hangs on the same two ports.
+lies side by side instead of on top of each other.
+
+There may also be **several transitions the same way round** between two states, `alarm` and
+`seen` from *Patrol* to *Chase*, say. They are told apart only by their name, so a further one is
+given a name of its own the moment it is made (`Transition 2`, `Transition 3`, skipping any name
+already leaving that state), and the inspector refuses a rename that would make two of them alike,
+the empty name included. They are drawn side by side like a there-and-back pair. In a behavior
+graph a second edge between the same two ports is still refused (`Already connected`).
 
 A transition may also lead from a state **back into itself**: after *Make transition*, click the
 same state again. It is drawn as a **loop over the top edge** of the node, and the inspector lists
 it once, under *out*. Taking it **re-enters** the state: `On state exited` and then
-`On state entered` fire for it, which is what it is for (attack again, restart a timer). Only
-states may do this; any other node connected to itself is still refused.
+`On state entered` fire for it, which is what it is for (attack again, restart a timer). A state
+may have more than one such loop, under different names; each further one is drawn outside the
+last. Only states may do this; any other node connected to itself is still refused.
 
 A transition can be **named**. Select a state and the inspector lists its transitions in two
 groups, *out* and *in*, each row with the state at the far end, a name field and a button to