feat(method): model template sources without inferential weights

[seonghobae]

Summary

• Adds method_effects: template, section, copied-text, style, modality, and corpus-background sources are explicit method structure.
• Those sources cannot be used as inferential topic weights (ADR 0004/0012).
• Source recovery is the computed match rate against known truth; a collapsed single-label assignment scores lower.

Claim boundary

• Estimator-side method-source vocabulary only. Does not remove stopwords, apply TF-IDF/BM25, or fit a topic model.
• No new migration number (#45 still owns 0007).
• Does not recreate in-flight crates (topic_measurement, psychometric_core, compute_backend, concept_dictionary, model_selection, interpretation_gateway, network_analysis, topic_lineage).

Test plan

• cargo test -p method_effects --offline --lib --tests
• cargo clippy -p method_effects --all-targets --offline -- -D warnings
• python3 scripts/check_docstrings.py
• python3 scripts/check_workspace_contract.py
• python3 scripts/validate_documentation.py
• Exact-head CI and independent review

[coderabbitai]

Important

Review skipped

Draft detected.

Please check the settings in the CodeRabbit UI or the .coderabbit.yaml file in this repository. To trigger a single review, invoke the @coderabbitai review command.

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro Plus

Run ID: db7dff5d-f118-42bf-ba8c-db44e4ce3e6c

You can disable this status message by setting the reviews.review_status to false in the CodeRabbit configuration file.

Use the checkbox below for a quick retry:

• 🔍 Trigger review

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands.}

[seonghobae]

Queue review for current head 90cc8b6:

• The PR is still a draft, so it is not merge-eligible.
• The displayed historical failed checks are cancelled workflow runs with no failed steps, not reproducible source failures.
• No source mutation or protected-branch bypass was made; promote the PR from draft only after its current head is ready and exact-head checks are rerun.

[seonghobae]

Superseded on protected main: crates/prompt_source/src/kind.rs provides PromptKind + refuse_prompt_as_unique_content/refuse_prompt_as_stopword_deletion; crates/style_source, crates/copied_text, crates/modality_source, crates/corpus_background provide the same source-family gates; and crates/stopword_deletion/src/lib.rs states "Repeated template, section, copied-text, style, modality, and corpus-background wording stays explicit method/background structure" — exactly this PR's MethodSourceKind enumeration, each crate exporting identity_recovery_rate. Method/template sources therefore carry no inferential weight on main.