feat(cli,docs): ship the ganged open examples + document the gang construct (#61 tasks 7-8)

The two open examples now expose their author-intended single knobs — the
closed builders always bound these pairs to one value by hand; the open forms
falsely offered them as independent axes:
- r_breakout_open: channel_hi.length + channel_lo.length -> channel_length
  (the Donchian channel is structurally ONE parameter)
- r_meanrev_open: mean_window.length + var_window.length -> window; the band
  factor stays an independent axis
Regenerated via the emitters (never hand-edited); the closed examples are
byte-unchanged. The carve builders gang in the open branch only.

Test migration: the two axis-namespace pins, five --real e2e invocations
(single gang axis, the 10,20 diagonal for the campaign pair — the mismatched
20,40/10,20 grid was exactly the configuration space the gang retires), and
the param_stability row counts (4 -> 3). The r-sma walkforward golden anchor
is untouched (it never swept a ganged pair).

Docs: authoring-guide gains the seventh op + the third param state
(open/bound/ganged) + the gang wrap note; README op list + Axis concept;
glossary gang entry; ledger C24 records the gang verb and the pre-ship
Tier-2 dormancy (no format-version bump while no out-of-repo reader exists).

Verified: full workspace suite 1104/0 (--real e2e included, local data
present), clippy -D warnings clean, cargo doc clean; live acceptance:
introspect --params prints channel_length:I64 alone / window:I64 +
band.factor:F64.

closes #61

docs/glossary.md

@@ -119,6 +119,16 @@ A node re-evaluates only when ≥1 of its own inputs is fresh this cycle; otherw
 **Avoid:** deploy artifact, standalone binary
 A statically-linked, versioned, frozen build, never hot-swapped (audit trail: this artifact = this commit). The general category; a `bot` is the specific case of a deployed strategy + broker.
 
+### gang
+**Avoid:** —
+A blueprint-level declaration that two or more sibling nodes' open params are
+semantically one knob. The member addresses leave the blueprint's parameter
+space; one gang address (a single path segment at the composite's level)
+replaces them, and its value fans out to every member at bootstrap. Binding is
+structural, not advisory — no consumer can bind a member independently. The
+gang's name is a debug/axis symbol (identity-blind); its member coordinates
+are identity-bearing. Declared by the `gang` op / `GraphBuilder::gang`.
+
 ### gross R
 **Avoid:** —
 The R-multiple outcome of the **signal alone** — per-trade R integrated by the R-evaluator with **no `cost model`** attached (the zero-cost baseline). `net R = gross R − cost-in-R` once a cost model is composed on.
@@ -293,7 +303,7 @@ The harness's structural parameterization — which strategy, instrument(s), bro
 
 ### sweep
 **Avoid:** param-sweep, parameter sweep
-An orchestration axis varying tuning params (grid or random) within a fixed structure. The inner, param-tuning loop, distinct from the structural experiment matrix. On a loaded blueprint every open knob (`--list-axes`) is **required** — a subset is refused with the missing knob named; pin an unwanted knob with a single-value axis (`--axis name=<one-value>`), there is no default. `aura sweep --axis` takes the `--list-axes`-printed, root-composite-wrapped name (e.g. `graph.fast.length`) — not the raw `param_space` name (`fast.length`) that `graph introspect --params` and a campaign document's axes use; the CLI strips exactly one leading wrapper segment (#210). The `aura sweep` CLI verb is now thin sugar over the `campaign document` path — its blueprint form (`<bp.json> --real`) translates to a generated, content-addressed campaign run through the one executor (#210); the built-in `--strategy` sweep surface was retired by #159 (its hard-wired harnesses removed) — sweep now runs from a blueprint + `--axis`, and a retired `--strategy` token falls to the generic usage error.
+An orchestration axis varying tuning params (grid or random) within a fixed structure. The inner, param-tuning loop, distinct from the structural experiment matrix. On a loaded blueprint every open knob (`--list-axes`) is **required** — a subset is refused with the missing knob named; pin an unwanted knob with a single-value axis (`--axis name=<one-value>`), there is no default. `aura sweep --axis` takes the `--list-axes`-printed, root-composite-wrapped name (e.g. `graph.fast.length`) — not the raw `param_space` name (`fast.length`) that `graph introspect --params` and a campaign document's axes use; the CLI strips exactly one leading wrapper segment (#210). The `aura sweep` CLI verb is now thin sugar over the `campaign document` path — its blueprint form (`<bp.json> --real`) translates to a generated, content-addressed campaign run through the one executor (#210); the built-in `--strategy` sweep surface was retired by #159 (its hard-wired harnesses removed) — sweep now runs from a blueprint + `--axis`, and a retired `--strategy` token falls to the generic usage error. A ganged pair contributes ONE axis.
 
 ### tap
 **Avoid:** —