rename: retire the stage1-* family for the r-family (r-sma / r-breakout / r-meanrev)

The stage1 ordinal has been dead vocabulary since the C10 reframe dropped
the two-stage research model: a 1 structurally implies a 2 that no longer
exists. The family is renamed by its live discriminator - the R yardstick -
with members named by their signal, uniform with their signal-named
siblings (sma, macd, momentum):

- selectors: stage1-r -> r-sma, stage1-breakout -> r-breakout,
  stage1-meanrev -> r-meanrev (old tokens are usage errors, exit 2 - no
  silent alias)
- identifiers: Strategy::RSma/RBreakout/RMeanRev, HarnessKind::RSma,
  r_sma_*/r_breakout_*/r_meanrev_*, wrap_r, run_signal_r, RGrid, R_SMA_*
- persisted identity: the sma_signal composite (param prefix
  sma_signal.fast.length / .slow.length; fixtures regenerated; content-ids
  shift - no test pins a literal hash, the registry parses no record names)
- e2e test files git-mv'd to r_sma_e2e / r_breakout_e2e / r_meanrev_e2e
- dead Stage-1/Stage-2 prose reworded to post-C10 vocabulary across
  rustdoc, Cargo.tomls, ledger live lines, and the glossary (historical
  entries stay; fieldtests corpus untouched)
- CLAUDE.md invariant 7 rewritten to record the ratified C10 reframe
  faithfully (the token-swap alone would have laundered the retired
  gated-currency/realistic-broker design into unmarked live prose); the
  unbacked account-mode clause dropped

Verification: cargo build/test --workspace green (51 targets), clippy
-D warnings clean, doc build clean, acceptance grep gate leaves exactly
the one resampling-stage false positive (harness.rs), smoke: --harness
r-sma runs, --harness stage1-r exits 2 with the new usage line.

Decision log: forks and rationale recorded on the issue (reconciliation
+ implementation-phase comments).

closes #174

crates/aura-cli/Cargo.toml

@@ -12,8 +12,8 @@ path = "src/main.rs"
 [dependencies]
 aura-core = { path = "../aura-core" }
 aura-engine = { path = "../aura-engine" }
-# aura-composites: the Stage-1 RiskExecutor / vol_stop composite-builders the
-# stage1-r harness wires (kept out of aura-engine so the engine stays domain-free).
+# aura-composites: the RiskExecutor / vol_stop composite-builders the
+# r-sma harness wires (kept out of aura-engine so the engine stays domain-free).
 aura-composites = { path = "../aura-composites" }
 aura-registry = { path = "../aura-registry" }
 aura-std = { path = "../aura-std" }