feat(method): refuse copied-text residue as unique content

ARCHITECTURE.md

@@ -61,6 +61,7 @@ boundaries above remain the target modular MSA architecture.
 | `tepp_simulation` | known-truth temporal/event data generation |
 | `validation_core` | RMSE, bias, coverage, graph, and Monte Carlo metrics |
 | `tepp_api` | versioned DTO, schema, and export contracts |
+| `copied_text` | copied-text residue is not unique latent content and not stopword deletion |
 
 No crate exposes placeholder production behavior in Task 1. This prevents an
 empty façade from becoming a de facto public API before its invariants and tests

CHANGELOG.md

@@ -6,6 +6,7 @@ All notable changes to TEPP are documented here. The format follows Keep a Chang
 
 ### Added
 
+- `copied_text` identity gate: copied and boilerplate residue is not unique latent content and is not erased by a stopword list; recovered copied-text kinds match known truth at a higher computed rate than collapsing every token to unique content (ADR 0004/0012).
 - `tepp_api` adaptive orchestration router (ADR 0010): versioned `direct`/`verify`/`committee`/`conductor`/`abstain` selection from CPU `f64` risk, ambiguity, evidence, and token-budget inputs; recorded stages, recursion, decomposition, access lists, and role-specific reasoning effort; fail-closed document-controlled policy/access/credentials; LLM plans remain proposals under deterministic statistical authority; comparable-budget ablation requires a direct baseline; credential-free contextual-orchestrator binding. Live NIM HTTP remains accepted-target.
 - `tepp_api` purpose-bound provider-payload minimization: time-bounded `PurposeGrant` evaluation, fail-closed expired/not-yet-valid/inverted/cross-tenant/impossible-calendar denial, semantic UTC calendar validation, refusal to copy identity mappings into model-provider payloads or ordinary logs, preservation of opaque analytical identifiers and membership roles (no blanket PII mask), a separately authorized scientific re-identification path, and an internally bound FIPS 180-4 SHA-256 audit digest appended through `ReidentificationAuditSink` before disclosure.
 - `persistence_postgres` backup/restore integrity: restored snapshots stay unusable until tenant, canonical `SHA-256`, knowledge-cutoff eligibility, temporal window order, and append-only triggers revalidate; SQL probes raise `restore integrity failed` (ADR 0013).

Cargo.toml

@@ -11,6 +11,7 @@ members = [
     "crates/tepp_simulation",
     "crates/validation_core",
     "crates/tepp_api",
+    "crates/copied_text",
 ]
 default-members = [
     "crates/evidence_core",
@@ -23,6 +24,7 @@ default-members = [
     "crates/tepp_simulation",
     "crates/validation_core",
     "crates/tepp_api",
+    "crates/copied_text",
 ]
 
 [workspace.package]

README.md

@@ -7,7 +7,7 @@ implemented in Rust.
 ## Current implementation state
 
 This branch establishes the Task 1 Rust workspace and quality-gate foundation.
-The ten bounded crates compile independently but intentionally expose no
+The eleven bounded crates compile independently but intentionally expose no
 placeholder production APIs. Domain behavior begins in Task 2 with immutable
 evidence identifiers and source records.
 
@@ -22,6 +22,7 @@ crates/corpus_split
 crates/tepp_simulation
 crates/validation_core
 crates/tepp_api
+crates/copied_text
 ```
 
 ## Local verification

crates/copied_text/Cargo.toml

@@ -0,0 +1,17 @@
+[package]
+name = "copied_text"
+description = "Copied-text residue is not unique content and not stopword deletion."
+version.workspace = true
+edition.workspace = true
+rust-version.workspace = true
+license.workspace = true
+authors.workspace = true
+repository.workspace = true
+homepage.workspace = true
+readme.workspace = true
+keywords.workspace = true
+categories.workspace = true
+publish = false
+
+[lints]
+workspace = true

crates/copied_text/src/error.rs

@@ -0,0 +1,55 @@
+//! Fail-closed copied-text errors.
+
+use std::fmt;
+
+/// A fail-closed copied-text error.
+#[derive(Clone, Copy, Debug, Eq, PartialEq)]
+#[non_exhaustive]
+pub enum CopiedTextError {
+    /// Copied-text residue was treated as unique latent content.
+    CopiedTextIsNotUniqueContent,
+    /// Copied-text residue was treated as stopword deletion.
+    CopiedTextIsNotStopwordDeletion,
+    /// A recovery slice was empty or length-mismatched.
+    InvalidCopiedPayload,
+}
+
+impl fmt::Display for CopiedTextError {
+    fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
+        let message = match self {
+            Self::CopiedTextIsNotUniqueContent => {
+                "copied-text residue is not unique latent content"
+            }
+            Self::CopiedTextIsNotStopwordDeletion => "copied-text residue is not stopword deletion",
+            Self::InvalidCopiedPayload => "invalid copied-text payload",
+        };
+        formatter.write_str(message)
+    }
+}
+
+impl std::error::Error for CopiedTextError {}
+
+#[cfg(test)]
+mod tests {
+    use super::CopiedTextError;
+
+    #[test]
+    fn error_messages_are_stable() {
+        for (error, message) in [
+            (
+                CopiedTextError::CopiedTextIsNotUniqueContent,
+                "copied-text residue is not unique latent content",
+            ),
+            (
+                CopiedTextError::CopiedTextIsNotStopwordDeletion,
+                "copied-text residue is not stopword deletion",
+            ),
+            (
+                CopiedTextError::InvalidCopiedPayload,
+                "invalid copied-text payload",
+            ),
+        ] {
+            assert_eq!(error.to_string(), message);
+        }
+    }
+}

crates/copied_text/src/kind.rs

@@ -0,0 +1,128 @@
+//! Copied-text residue versus unique latent content.
+
+use crate::CopiedTextError;
+
+/// Closed vocabulary of copied-text token treatments.
+#[derive(Clone, Copy, Debug, Eq, PartialEq)]
+pub enum CopiedKind {
+    /// Copied or boilerplate residue, not unique document meaning.
+    CopiedText,
+    /// Token treatment reserved for unique latent content.
+    UniqueContent,
+}
+
+impl CopiedKind {
+    /// Return the stable wire kind name.
+    #[must_use]
+    pub const fn wire_name(self) -> &'static str {
+        match self {
+            Self::CopiedText => "copied_text",
+            Self::UniqueContent => "unique_content",
+        }
+    }
+
+    /// Parse a stable wire kind name.
+    ///
+    /// # Errors
+    ///
+    /// Returns [`CopiedTextError::InvalidCopiedPayload`] for unrecognized names.
+    pub fn from_wire_name(name: &str) -> Result<Self, CopiedTextError> {
+        match name {
+            "copied_text" => Ok(Self::CopiedText),
+            "unique_content" => Ok(Self::UniqueContent),
+            _ => Err(CopiedTextError::InvalidCopiedPayload),
+        }
+    }
+}
+
+/// Refuse to treat copied-text residue as unique latent content.
+///
+/// # Errors
+///
+/// Returns [`CopiedTextError::CopiedTextIsNotUniqueContent`] when `kind` is
+/// [`CopiedKind::CopiedText`].
+pub fn refuse_copied_text_as_unique_content(kind: CopiedKind) -> Result<(), CopiedTextError> {
+    match kind {
+        CopiedKind::CopiedText => Err(CopiedTextError::CopiedTextIsNotUniqueContent),
+        CopiedKind::UniqueContent => Ok(()),
+    }
+}
+
+/// Refuse to treat copied-text residue as stopword deletion.
+///
+/// # Errors
+///
+/// Returns [`CopiedTextError::CopiedTextIsNotStopwordDeletion`] when `kind` is
+/// [`CopiedKind::CopiedText`].
+pub fn refuse_copied_text_as_stopword_deletion(kind: CopiedKind) -> Result<(), CopiedTextError> {
+    match kind {
+        CopiedKind::CopiedText => Err(CopiedTextError::CopiedTextIsNotStopwordDeletion),
+        CopiedKind::UniqueContent => Ok(()),
+    }
+}
+
+/// Fraction of recovered copied-text kinds that match known truth.
+///
+/// # Errors
+///
+/// Returns [`CopiedTextError::InvalidCopiedPayload`] when either slice is
+/// empty or the lengths differ.
+pub fn identity_recovery_rate(
+    truth: &[CopiedKind],
+    decided: &[CopiedKind],
+) -> Result<f64, CopiedTextError> {
+    if truth.is_empty() || truth.len() != decided.len() {
+        return Err(CopiedTextError::InvalidCopiedPayload);
+    }
+    let mut matches = 0_u32;
+    for (truth_kind, decided_kind) in truth.iter().zip(decided) {
+        if truth_kind == decided_kind {
+            matches += 1;
+        }
+    }
+    Ok(f64::from(matches) / truth.len() as f64)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::{
+        CopiedKind, identity_recovery_rate, refuse_copied_text_as_stopword_deletion,
+        refuse_copied_text_as_unique_content,
+    };
+    use crate::CopiedTextError;
+
+    #[test]
+    fn local_branches_cover_kinds_payloads_and_wire_names() {
+        assert_eq!(
+            refuse_copied_text_as_unique_content(CopiedKind::CopiedText),
+            Err(CopiedTextError::CopiedTextIsNotUniqueContent)
+        );
+        assert_eq!(
+            refuse_copied_text_as_stopword_deletion(CopiedKind::CopiedText),
+            Err(CopiedTextError::CopiedTextIsNotStopwordDeletion)
+        );
+        refuse_copied_text_as_unique_content(CopiedKind::UniqueContent).expect("unique");
+        refuse_copied_text_as_stopword_deletion(CopiedKind::UniqueContent).expect("unique");
+        for kind in [CopiedKind::CopiedText, CopiedKind::UniqueContent] {
+            assert_eq!(
+                CopiedKind::from_wire_name(kind.wire_name()).expect("round-trip"),
+                kind
+            );
+        }
+        assert_eq!(
+            CopiedKind::from_wire_name("stopword"),
+            Err(CopiedTextError::InvalidCopiedPayload)
+        );
+        let matched = identity_recovery_rate(&[CopiedKind::CopiedText], &[CopiedKind::CopiedText])
+            .expect("rate");
+        assert!((matched - 1.0).abs() < f64::EPSILON);
+        assert_eq!(
+            identity_recovery_rate(&[], &[]),
+            Err(CopiedTextError::InvalidCopiedPayload)
+        );
+        assert_eq!(
+            identity_recovery_rate(&[CopiedKind::CopiedText], &[]),
+            Err(CopiedTextError::InvalidCopiedPayload)
+        );
+    }
+}

crates/copied_text/src/lib.rs

@@ -0,0 +1,22 @@
+#![forbid(unsafe_code)]
+#![deny(missing_docs)]
+#![allow(clippy::cast_precision_loss)]
+//! Copied-text residue is not unique latent content.
+//!
+//! Copied and boilerplate passages stay explicit method/background structure.
+//! They are not unique document meaning and are not erased by a stopword list
+//! (ADR 0004/0012).
+
+mod error;
+mod kind;
+
+/// Fail-closed copied-text errors.
+pub use error::CopiedTextError;
+/// Closed vocabulary of copied-text token treatments.
+pub use kind::CopiedKind;
+/// Fraction of recovered copied-text kinds that match known truth.
+pub use kind::identity_recovery_rate;
+/// Refuse to treat copied-text residue as stopword deletion.
+pub use kind::refuse_copied_text_as_stopword_deletion;
+/// Refuse to treat copied-text residue as unique latent content.
+pub use kind::refuse_copied_text_as_unique_content;

crates/copied_text/tests/copied_text_contract.rs

@@ -0,0 +1,67 @@
+//! Copied-text residue is not unique content and not stopword deletion.
+
+use copied_text::{
+    CopiedKind, CopiedTextError, identity_recovery_rate, refuse_copied_text_as_stopword_deletion,
+    refuse_copied_text_as_unique_content,
+};
+
+#[test]
+fn copied_text_cannot_become_unique_content_or_stopword_deletion() {
+    assert_eq!(
+        refuse_copied_text_as_unique_content(CopiedKind::CopiedText),
+        Err(CopiedTextError::CopiedTextIsNotUniqueContent)
+    );
+    assert_eq!(
+        refuse_copied_text_as_stopword_deletion(CopiedKind::CopiedText),
+        Err(CopiedTextError::CopiedTextIsNotStopwordDeletion)
+    );
+    refuse_copied_text_as_unique_content(CopiedKind::UniqueContent).expect("unique");
+    refuse_copied_text_as_stopword_deletion(CopiedKind::UniqueContent).expect("unique");
+}
+
+#[test]
+fn recovered_kinds_match_known_truth_better_than_a_unique_content_collapse() {
+    let truth = [
+        CopiedKind::CopiedText,
+        CopiedKind::UniqueContent,
+        CopiedKind::CopiedText,
+    ];
+    let recovered = truth;
+    let collapsed = [
+        CopiedKind::UniqueContent,
+        CopiedKind::UniqueContent,
+        CopiedKind::UniqueContent,
+    ];
+    let recovered_rate = identity_recovery_rate(&truth, &recovered).expect("recovered");
+    let collapsed_rate = identity_recovery_rate(&truth, &collapsed).expect("collapsed");
+    let expected = {
+        let mut matches = 0_u32;
+        for (truth_kind, decided_kind) in truth.iter().zip(recovered.iter()) {
+            if truth_kind == decided_kind {
+                matches += 1;
+            }
+        }
+        f64::from(matches) / f64::from(u32::try_from(truth.len()).expect("len"))
+    };
+    assert!((recovered_rate - expected).abs() < f64::EPSILON);
+    assert!(recovered_rate > collapsed_rate);
+}
+
+#[test]
+fn empty_or_mismatched_kind_payloads_fail_closed() {
+    assert_eq!(
+        identity_recovery_rate(&[], &[]),
+        Err(CopiedTextError::InvalidCopiedPayload)
+    );
+    assert_eq!(
+        identity_recovery_rate(&[CopiedKind::CopiedText], &[]),
+        Err(CopiedTextError::InvalidCopiedPayload)
+    );
+    assert_eq!(
+        identity_recovery_rate(
+            &[CopiedKind::CopiedText, CopiedKind::UniqueContent],
+            &[CopiedKind::CopiedText]
+        ),
+        Err(CopiedTextError::InvalidCopiedPayload)
+    );
+}

crates/copied_text/tests/crate_contract.rs

@@ -0,0 +1,7 @@
+//! Integration contract for the `copied_text` package identity.
+
+#[test]
+fn package_identity_is_stable() {
+    let observed = std::hint::black_box(env!("CARGO_PKG_NAME"));
+    assert_eq!(observed, "copied_text");
+}

docs/TRACEABILITY.md

@@ -25,7 +25,7 @@ The full APA 7th standards/literature register remains `docs/research/standards-
 | TRSL-TM temporal/relational topic posterior and backend compatibility | ADR 0012; ADR 0004 | future `topic_measurement` | accepted-target |
 | global P0 topic identity with activity/dormancy/reactivation | ADR 0012 | future topic lineage/activity state | accepted-target |
 | no default stopword deletion / no TF-IDF-BM25 inferential weighting | ADR 0004/0012; PRD/TRD | future semantic/method-source model | accepted-target |
-| report template/section/copied/style/modality method effects | ADR 0004/0012; PRD/TRD | simulation truth factors implemented; estimator-side method model remains future | partial |
+| report template/section/copied/style/modality method effects | ADR 0004/0012; PRD/TRD | simulation truth factors implemented; `copied_text` copied-versus-unique-content identity on the active PR; estimator-side method model remains future | partial |
 | candidate K statistical/Pareto gates + blinded LLM review | ADR 0012; research | future `model_selection` | accepted-target |
 | compositional topic correlation / stable clustering | ADR 0005/0012; research | future `network_analysis` | accepted-target |
 | posterior ESEM / longitudinal invariance / DSEM | ADR 0005 | future `psychometric_core` | accepted-target |

docs/adr/0004-shared-multilingual-latent-space.md

@@ -1,7 +1,7 @@
 # ADR 0004 — Shared multilingual latent semantic space
 
 **Decision status:** Accepted  
-**Implementation maturity:** accepted-target  
+**Implementation maturity:** accepted-target — copied-versus-unique-content identity in `copied_text` on the active PR; shared-space estimators remain accepted-target  
 **Date:** 2026-08-05  
 **Supersedes:** None. ADR 0012 governs the complete topic-estimator/backend/global-topic contract built on this multilingual measurement decision.
 

docs/adr/0012-temporal-relational-shared-latent-topic-measurement.md

@@ -1,7 +1,7 @@
 # ADR 0012 — Temporal Relational Shared-Latent Topic Measurement
 
 **Decision status:** Accepted  
-**Implementation maturity:** accepted-target  
+**Implementation maturity:** accepted-target — copied-versus-unique-content identity in `copied_text` on the active PR; estimator-side method model remains accepted-target  
 **Date:** 2026-08-12  
 **Supersedes:** None; refines ADR 0004 and ADR 0005 without replacing their multilingual and psychometric authorities.