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

.gitignore

@@ -0,0 +1,32 @@
+# Allowlist ignore file, per the house convention: ignore everything, then
+# explicitly re-admit tracked paths.
+**/*
+
+!.gitignore
+!README.md
+!pyproject.toml
+!uv.lock
+
+!profile/
+!profile/**
+
+!news/
+!news/**
+
+!tests/
+!tests/**
+
+!deploy/
+!deploy/**
+
+# Re-exclude generated and local artifacts that would otherwise slip through
+# the directory re-admissions above.
+news/**/__pycache__/**
+news/**/*.pyc
+tests/**/__pycache__/**
+tests/**/*.pyc
+**/*.db
+**/*.db-wal
+**/*.db-shm
+**/*.npy
+.venv/**