feat(research,composites,cli,docs): vol_tf — the timescale-matched stop regime

The second risk-regime variant vol_tf{period_minutes, length, k}
computes the vol estimator over completed time buckets: an H1 signal
gets an H1-matched stop in the research matrix instead of a hand-scaled
minute stop (the issue's k-inflation workaround retires). Additive
externally-tagged serde (stored Vol documents keep their content ids);
the executor arm wires the VolTfStop primitive via the builder+bind
chain; validate checks period_minutes/length/k positivity per regime.

The member-manifest round-trip holds for both variants (C1): vol_tf
members stamp stop_period_minutes/stop_length/stop_k and the reproduce
path re-derives the VolTf stop whenever stop_period_minutes is present
— never a silent default-Vol fallback. The Regimes slot label and the
unit notes name the new variant (period_minutes IS the stop's
timescale); glossary, authoring guide, and design ledger record the
second variant. Default regime and sugar paths byte-untouched.

Coverage: node units (rollover-only emission, bucket-delta math, the
constant-|delta| correspondence with the per-cycle regime), executor
fold, serde/validate units, the manifest round-trip unit, and a
hostless two-regime e2e (distinct ordinals; vol_tf members stamp their
timescale, vol members do not).

closes #262

docs/authoring-guide.md

@@ -468,7 +468,7 @@ open slot: format_version (required, must be 1)
 open slot: kind (required, must be "campaign")
 open slot: name (required, string)
 open slot: data (required section: instruments + windows)
-open slot: risk (optional, list of stop regimes { vol: { length, k } }; absent = one default regime)
+open slot: risk (optional, list of stop regimes { vol: { length, k } } | { vol_tf: { period_minutes, length, k } }; absent = one default regime)
 open slot: cost (optional, list of cost models { constant: { cost_per_trade } } | { vol_slippage: { slip_vol_mult } } | { carry: { carry_per_cycle } }; absent = zero cost, net = gross)
 open slot: strategies (required, non-empty list of { ref, axes })
 open slot: process.ref (required, content id of a process document)

docs/design/INDEX.md

@@ -993,8 +993,9 @@ blueprint-data (#159, cuts 1b-4); `run` is now blueprint-driven — `aura run
 **Realization (2026-07-06 — the risk regime as a structural campaign axis, #210).**
 The `StopRule{Fixed,Vol}` structural axis is realized at the campaign-document
 level as `CampaignDoc.risk: [RiskRegime]` (a serializable, content-addressable
-mirror of the runtime enum — `aura-research`, sole variant `Vol{length,k}`, the
-fixed-stop rule additive when needed). It is a **kept-separate** matrix axis, a
+mirror of the runtime enum — `aura-research`, variants `Vol{length,k}` and
+`VolTf{period_minutes,length,k}` (#262), the fixed-stop rule additive when
+needed). It is a **kept-separate** matrix axis, a
 peer of instruments and windows: the executor keys the nominee map by
 `(strategy, window, regime)`, so generalize aggregates across instruments
 *within* a regime, never across regimes. Regimes are therefore **compared** at

docs/glossary.md

@@ -232,13 +232,14 @@ A node that converts a finer stream to a coarser bar stream, emitting a complete
 ### risk regime
 **Avoid:** 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
+serializable protective-stop regime (variants `vol{length,k}` — per-cycle —
+and `vol_tf{period_minutes,length,k}` — per completed time bucket) 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 — in `vol{length,k}` (stop = k·√EMA(Δ², length) over
 m1 cycles) `length` only smooths the vol estimator while `k` scales the stop
-distance, so the stop's timescale stays one cycle (#262 tracks a
-timescale-matched variant).
+distance, so the stop's timescale stays one cycle (`vol_tf` sets the stop's
+timescale via `period_minutes`).
 
 ### run
 **Avoid:** —