feat(agent): group ingestion proposals by learning

protocols/CONTRIBUTIONS.md

@@ -10,6 +10,10 @@ Use the stable principal ID assigned to the configured agent credential. The cre
 
 Capture tools stage and archive source material but do not register its source record. Before evaluating a proposal that cites a newly captured source, include the exact returned `source_candidate` as a `register_source` operation in the same proposal, or confirm that the source revision was already accepted and is readable. Use the candidate's exact `revision_id` as each citation's `source_revision_id`, and the capture's returned `extraction_id`; do not synthesize or copy IDs from another capture. A source operation and a node operation may be evaluated together.
 
+Every source registration affects both the shared-source policy and each project in `source.ingested_for`; therefore proposal scope must set `include_shared=true` and explicitly include the project(s), and the agent credential must be authorized for that scope. A project-only scope is invalid for a newly registered source even if it is relevant only to that project.
+
+Before creating a new node, search the explicit project and shared scope with multiple lexical queries: the proposed title, distinctive terms, aliases and likely synonyms. Inspect plausible matches with `get_node`. If the finding belongs to an existing node, preserve its stable ID and supported content when proposing an evidence-backed update; do not create a second node for the same concept. Keep materially different populations, time periods, settings, mechanisms or conclusions distinct. Similarity is only a review cue. The backend flags exact entity name/alias matches but does not detect duplicate notes, cases, concepts or datapoints; if likely duplicates remain unresolved after search, submit a non-blocking review flag and do not create another node yet.
+
 Finalize claim text and evidence before creating support assessments or digests. Every evidence `assertion_path` must name its exact typed claim field (`claims[n].text`, `assumptions[n].text` or `limitations[n].text`). Its `assertion_digest` must bind to that exact claim text. Set the assessment's `assertion_digest` to the same value and `evidence_digests` to the digests of the claim's final evidence objects. Any edit to claim text or evidence requires regenerating those dependent values and the proposal `payload_digest` before `proposal_evaluate`.
 
 Use the canonical GEWU digest rules, not a hash of the raw quote or raw request text. Canonical JSON is UTF-8 JSON with Unicode preserved, sorted keys, no insignificant whitespace and no NaN values. The assertion digest is SHA-256 of canonical JSON `{"assertion": normalized_text}`, where text has CRLF and CR converted to LF and is normalized to Unicode NFC. An evidence digest is SHA-256 of canonical JSON for the complete evidence object in schema JSON form. The assessment's `evidence_digests` must match those final evidence digests. The proposal payload digest is SHA-256 of canonical JSON for the final operations serialized as GEWU v1 contract records. Recompute it after adding/removing/changing any operation. If the client cannot reproduce these rules, stop before submission and report that digest generation is unavailable.