test(cli),docs: risk-axis introspection pins + guide/glossary coverage (#216 slice 2)

closes #216

The remaining introspection e2e pins: the bare-{} envelope probe (the
issue's exact reproduction) lists the optional risk slot; a bound
(non-empty) risk list closes it (no open slots); an EXPLICIT empty
'risk': [] still counts as open (pins the non-emptiness branch, which an
is_none()-based probe would get wrong); the --block std::risk assert is
sharpened to pin the optional rendering and the block doc line (the old
bare contains("risk") matched std::risk trivially).

Docs: the authoring guide's bare-{} transcript gains the risk line, the
§3 worked example gains a two-regime risk section (heading updated), a
prose paragraph explains the structural risk axis (stop defines R;
absent = the same default vol regime the verbs bind), and both validate
transcripts show the new matrix counts. The glossary gains the
'risk regime' entry (canonical term; avoid: stop regime, risk section).

Verified: cargo test --workspace 62 result groups / 0 failures; clippy
-D warnings clean; cargo doc 0 warnings; the guide's transcript strings
grep-match the shipped hint/summary bytes (1/2/1).

docs/glossary.md

@@ -211,6 +211,14 @@ The per-symbol composite turning a bias into a managed position, **in R**: `stop
 **Avoid:** —
 A node that converts a finer stream to a coarser bar stream, emitting a completed bar only at the boundary so no partial bar ever leaks (enforcing no look-ahead). Clock-sensitive.
 
+### risk regime
+**Avoid:** stop regime, risk section
+One entry of a campaign document's structural risk axis (`risk`): a
+serializable protective-stop regime (sole variant `vol{length,k}`) the matrix
+runs every cell under, so cells differ by execution discipline, never by
+signal. Absent or empty = one implicit default regime; the regime's stop
+defines the risk unit R.
+
 ### run
 **Avoid:** —
 One execution recorded in the run registry as a manifest + metrics — the registry-record framing of an execution. Distinct from `sim` (the executable unit) and `backtest` (the replay framing).