fix: isolate production universe in capacity research

docs/research/portfolio-capacity-bracket.md

@@ -22,6 +22,11 @@ Because the current ~505-name production membership is projected backward,
 paired arm-versus-control differences are the primary evidence. Absolute
 profitability is descriptive and survivorship-biased.
 
+Implementation correction: the first completed v1 artifact at commit `23fe39f`
+incorrectly allowed the snapshot's broad rank-only universe to submit trades.
+That artifact is invalid, is removed from the branch, and must not be used for
+strategy conclusions. Runner v2 fixes the construction/ranking partition below.
+
 ## Frozen arms
 
 1. **cap10_incumbent:** exact production-style cap-10 control, no displacement.
@@ -37,6 +42,12 @@ live-like full-universe residual-momentum/low-volatility 80/20 rank, activation
 threshold 80, normal gate-reset re-entry, close fill, 3×ATR trail, 30-session
 maximum hold, 1% risk, and costs of 0.10% and 0.20% per fill.
 
+Every priced symbol contributes to the daily cross-sectional rank. Only symbols
+not listed in the snapshot's `research_rank_only` side table may submit trade
+setups to any arm. The resulting construction universe must contain 450-600
+symbols (expected approximately 505); validation fails outside that frozen
+guardrail or when the side table references unknown ticker symbols.
+
 The daily replay uses zero outcome horizon: setup and rank observations continue
 through the snapshot's last session because portfolio simulation, unlike outcome
 grading, does not require 30 future bars.
@@ -83,7 +94,8 @@ positions liquidate at the last measurement close with costs.
 
 The validate-only mode must print realized cohort counts and fail unless both
 protocols contain the seven annual clusters 2019–2025 and every warm anchor has
-at least 12 seeds.
+at least 12 seeds. It must also print ranking, rank-only, and tradable symbol
+counts plus the raw, removed, and retained qualified-long counts.
 
 ## Reporting
 
@@ -120,6 +132,12 @@ atomically and resume verifies a fingerprint over the implementation commit,
 this specification hash, snapshot SHA-256, cache key, arm definitions, costs,
 and cohort manifest. An authoritative run refuses a dirty worktree.
 
+The existing v1 candidate/rank cache is intentionally reusable: its
+full-universe current-day ranks are correct. Runner v2 derives a fingerprinted
+construction view by removing qualified rows whose symbols are rank-only. V2
+uses a versioned checkpoint directory, so invalid v1 portfolio cells are never
+resumed and the expensive daily rank replay does not need to run again.
+
 The loader reads only ticker ID/symbol and the OHLCV columns used by replay, so
 snapshots created before SEC metadata added `tickers.cik`, `tickers.sic`, and
 `tickers.sic_description` remain valid. Do not migrate or alter the research