Seed the rewrite: profile, calibration, and repo scaffolding

Ground-up replacement for news_triage, whose signal quality failed because it
had no representation of what its user likes -- three keywords fed to BM25 plus
a two-term substring blocklist.

profile/ holds the taste model as prose and TOML: 11 interest blocks, 3 veto
blocks, 5 importance blocks, each a set of probe sentences to be embedded.

The [scoring] constants are fitted, not guessed. CALIBRATION.md records the
measurements against all 3,885 items in the v0.2 database and 40 real feedback
labels, including two findings that changed the design:

- compare blocks by z-score within block, never raw cosine; raw cosine let
  geopolitics win 78% of items and buried known-liked items at median rank 1246
  of 3885 (293 after normalizing)
- veto needs a margin over the interest signal, not a threshold; a plain 0.55
  cutoff falsely killed "Belgian mayor blocks club from hosting Israeli opponent
  in Europa League", which the old substring blocklist also killed

README.md

@@ -0,0 +1,53 @@
+# news
+
+A personal news aggregator: many sources in, two to five well-chosen push
+notifications and one readable daily digest out.
+
+This is a ground-up rewrite of [`news_triage`](../news_triage), which is still
+running. The rewrite exists because the old system had no representation of what
+its user actually likes — its whole preference model was three keywords fed to
+BM25 plus a two-term substring blocklist, and everything else was ranking
+machinery with nothing meaningful to rank.
+
+## The core idea
+
+Taste is a set of **vectors**, not a bag of keywords.
+
+Every interest, veto and importance category in [`profile/profile.toml`](profile/profile.toml)
+is written as prose and embedded with a small CPU model (`bge-small-en-v1.5`,
+~130 MB, ONNX, no torch, no GPU — so it never contends with the llama-swap stack).
+An item's score is the max cosine similarity across a block's probes, never the
+mean: averaging "Middle East geopolitics" with "grid-scale energy storage" gives
+a vector near neither.
+
+This is what lets a topic be expressed as a *region* rather than a string. The
+old system could not represent "sports" as a concept, only as the literal
+characters `s-p-o-r-t-s`, which is why 18 of its 32 feedback clicks were its user
+hand-rejecting baseball recaps that `blocklist = ["sports"]` never matched.
+
+A generative LLM is used only for prose — the daily digest write-up and cluster
+headlines — at roughly 1–30 calls/day through LiteLLM, never for per-item scoring.
+
+## Two routing lanes
+
+Notifications are decided on two independent axes, because "something I might
+like" and "something I need to know about" are different questions:
+
+- **interest** — high similarity to the profile's interest vectors.
+- **importance** — burst velocity, independent-source-bucket count, editorial
+  prominence, and aggregator-native scores. Deliberately *not* raw corroboration
+  count, which just measures how many wire-reprinting outlets you subscribed to.
+
+Vetoes are absolute on **both** lanes. In the old system the bypass lane ignored
+relevance entirely, so a blocklisted item could still fire at priority 5.
+
+## Layout
+
+    profile/     the user's taste, as prose and as TOML. Start here.
+    news/        the pipeline: sources, store, embed, cluster, score, route, deliver
+    tests/
+    deploy/
+
+## Status
+
+Early. `profile/` is written; the pipeline is not yet built.