test: pin command dispatch to C's command.c switch (closes #31)

Audits every case label in C's command.c against this port's dispatch and
leaves the audit behind as a standing test, so the two lists cannot drift
again. A missing dispatch entry is the one porting error that leaves no
trace at build time: the port is function-by-function, so every C function
has a Go counterpart and a dropped key dangles nothing, fails to compile
nowhere, and simply answers "illegal command" the first time a player
presses it. That is how '+' (#11) survived until PR #30 found it by
accident.

Result: no further missing keys. '+' was the only one. Recording that as a
negative result — the class of bug is real, it has now been searched for
exhaustively rather than stumbled upon, and the search came back empty.
Eighty labels: sixty-five in the main switch, fifteen in the wizard
sub-switch.

commandHandlers is pinned by set equality in both directions. A missing key
is the '+' bug; an extra key is the same bug mirrored, since the likeliest
way to acquire one is promoting a key out of the wizard sub-switch, which
would expose a MASTER debug command in ordinary play. The main-switch keys
that commandHandlers cannot hold - the goto-over re-dispatches, F-to-f, 'a'
and 'm' - are covered separately through dispatchKey, because dropping one
of those is just as silent as dropping a map entry.

Two traps are documented in the file. rogue.h 52-53 defines when as
break;case, so a grep for 'case ' finds ten of the eighty labels. And the
main/wizard split is load-bearing: '+' was a divergence in ordinary play,
not just wizard mode, precisely because it is a main-switch key.

Confirms this port targets the MASTER build: all four #ifdef MASTER sites
in command.c are ported unconditionally, as is sticks.c 237.

TODO.md

@@ -49,7 +49,7 @@ wizard commands).
   extra key is the same bug mirrored — a MASTER debug command leaking into
   ordinary play. Two traps make this audit harder than it sounds and are
   documented in the file: `rogue.h` 52-53 defines `when` as `break;case`, so a
-  grep for `case ` finds six of the eighty labels; and the main/wizard split is
+  grep for `case ` finds ten of the eighty labels; and the main/wizard split is
   load-bearing, since `'+'` was a divergence in ordinary play precisely because
   it is a main-switch key. Confirms the port targets the MASTER build — all four
   `#ifdef MASTER` sites in `command.c` are ported unconditionally, as is

game/dispatch_test.go

@@ -23,7 +23,7 @@ import (
 //	#define otherwise	break;default
 //
 // The labels are therefore written "when 'x':", and a grep for "case "
-// finds six of the eighty. CTRL is extern.h:113, (c & 037); ESCAPE is
+// finds ten of the eighty. CTRL is extern.h:113, (c & 037); ESCAPE is
 // rogue.h:121, 27.
 //
 // There are two switches and the split between them is load-bearing. A