config: the clinical assistant answers from 12 excerpts

It asked for 8 while the reranker capped everything at 12, so 8 is what it ever
actually received — and its answers were judged good on that. Now that the cap
defers to the caller, 12 is the number worth asking for: it is what the corpus
has been tuned against, and the reranker still decides which 12.

Verified live: the assistant returns 12 sources.

Also records PubMed as a search source of its own rather than a provider option
under web search. It returns structured records — title, journal, year, PMID,
abstract — so a reference can be exact instead of reconstructed from a page
title, and a model should be able to reach for "the literature" distinctly from
"the web".

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Dv6sqaY6Vq3ChZHMem3cnU

TODO.md

@@ -179,3 +179,20 @@ The preview works now, but it is currently all-or-nothing. Intended shape:
   interesting part: because preview deliberately has no identity, the transcript
   has to be held client-side and replayed on the first authenticated request,
   not looked up server-side. Size-cap it and drop it on sign-out.
+
+## PubMed as a search source of its own
+
+Web search reaches the open web through Tavily, Serper, Brave or a self-hosted
+SearXNG. PubMed is a different kind of source and deserves its own tool rather
+than being a site: filter on a search engine.
+
+- E-utilities (esearch then efetch) needs no key for modest use, and an
+  NCBI_API_KEY raises the rate limit. No commercial third party either way.
+- It returns structured records — title, journal, year, PMID, abstract — so a
+  citation can be exact rather than reconstructed from a page title. That is the
+  real argument for a separate tool: the References section could carry a PMID.
+- A separate tool, not a provider option, because the model should be able to
+  reach for "the literature" distinctly from "the web": one search per resource
+  each, and a resource may legitimately want both.
+- Same guardrails as web search: admin-enabled, opt-in per generation, only the
+  query leaves, and hidden entirely when unavailable.

docs/retrieval-tuning.md

@@ -53,7 +53,7 @@ clamped on read so a bad value cannot break a search.
 
 | Feature | Keys | Default | Clamp |
 |---|---|---|---|
-| Clinical Assistant | `clinical_assistant.search_limit`, `clinical_assistant.context_chars` | 8, 1400 | 3–20, 300–4000 |
+| Clinical Assistant | `clinical_assistant.search_limit`, `clinical_assistant.context_chars` | 12, 1400 | 3–20, 300–4000 |
 | Learning Hub | `learning.search_limit`, `learning.context_chars` | 30, 2500 | 3–60, 300–8000 |
 | My Resources | *the same `learning.*` keys* | 30, 2500 | 3–60, 300–8000 |