Dumb OMO commit

.omo/evidence/fix-f2f3-news-triage.txt

@@ -0,0 +1,117 @@
+F2/F3 fix verification — news-triage
+====================================
+Date: 2026-09-01
+Workspace: /home/connor/docs/projects/news
+
+Scope
+-----
+Two reviewer findings from final-wave verification:
+- F2: relevance/importance percentiles were computed from the current poll batch only
+  instead of the trailing-7-day distribution required by the draft spec.
+- F3: blocklist veto sets relevance to f64::NEG_INFINITY; serde_json serializes
+  non-finite f64 as null, and news-web declared `relevance: f64`, causing the
+  entire /api/stories response to fail deserialization when any blocklisted item
+  was present.
+
+Implementation status
+---------------------
+The code fixes for both F2 and F3 were already present in the repository's
+initial commit (`20a6c26`). This session verified them, applied `cargo fmt`,
+and produced this evidence file and the notepad entries below. The only code
+delta introduced by this session is the formatting commit `676a0b7`.
+
+Fix A — trailing-7-day percentile ranks (F2)
+--------------------------------------------
+1. `crates/news-store/src/percentile.rs`
+   - `PercentileTracker::percentile_rank(metric_kind, value, window_days)` exists.
+   - Loads the same trailing window as `PercentileTracker::percentile`, computes
+     `(below + equal/2) / count * 100` via a numerically stable `mul_add`, and
+     returns `StoreError::InsufficientData` when the window is empty.
+   - Unit tests present:
+     - `percentile_rank_on_empty_window_returns_insufficient_data`
+     - `percentile_rank_of_one_to_ten_is_exact`
+     - `percentile_rank_excludes_out_of_window_rows`
+     - `neg_infinity_sorts_lowest_without_poisoning_finite_ranks`
+
+2. `crates/news-server/src/scheduler/cycle.rs`
+   - Batch-local `Vec<f64>` collectors and local `percentile_rank` helper removed.
+   - Each scored cluster calls:
+     - `tracker.percentile_rank(MetricKind::Relevance, relevance, 7)`
+     - `tracker.percentile_rank(MetricKind::Importance, importance, 7)`
+   - Cold-start rule: the draft specifies the cold-start rule only for the
+     relevance *score* ("BM25-only until 20 feedback samples exist") and does not
+     specify a percentile fallback. On `StoreError::InsufficientData` the code
+     maps to `0.0` with `tracing::info!("trailing ... percentile unavailable: {err}")`.
+     This is conservative: no threshold-based notify/digest until the 7-day window
+     has data; the bypass lane (`source_count >= 2`) remains percentile-independent.
+
+3. `crates/news-server/src/api/stories.rs`
+   - Duplicated local `percentile_rank` helper removed.
+   - `build_rows` creates a `PercentileTracker` and calls the shared rank method
+     for both metrics.
+
+4. `crates/news-cli/src/replay.rs`
+   - Third duplicated local `percentile_rank` helper removed.
+   - Uses `tracker.percentile_rank(..., 7)` for both metrics.
+   - Replay determinism is preserved because the in-memory DB accumulates samples
+     in fixture order before any rank is queried.
+
+Fix B — honest JSON boundary for blocklist veto (F3)
+----------------------------------------------------
+1. `crates/news-server/src/api/stories.rs`
+   - `StoryRow.relevance` is `Option<f64>` populated with
+     `relevance.is_finite().then_some(relevance)` so NEG_INFINITY serializes as
+     JSON `null`.
+   - Regression tests present:
+     - `blocklisted_story_serializes_relevance_as_null` — asserts `"relevance": null`
+     - `finite_relevance_serializes_as_number` — asserts finite relevance stays a number
+
+2. `crates/news-web/src/api.rs`
+   - `StoryRow.relevance` is `Option<f64>`.
+   - `fmt_score_option` helper present for rendering.
+   - Host-target decode regression tests present:
+     - `story_row_with_null_relevance_decodes`
+     - `story_row_with_finite_relevance_decodes`
+
+3. `crates/news-web/src/story_list.rs`
+   - Renders `—` for `None` relevance; the decision pill still shows `Suppress` + reason.
+
+4. `importance` left as `f64`
+   - Importance is finite by construction today (multi-hot arithmetic, no veto
+     path). No latent non-finite hazard was identified for that field.
+
+Cold-start rule (recorded in decisions.md)
+------------------------------------------
+Draft quote: the draft specifies the cold-start rule only for the relevance *score*
+("BM25-only until 20 feedback samples exist"; `.omo/drafts/news-triage.md:45`)
+and does not specify a percentile fallback. Therefore: on
+`StoreError::InsufficientData` from the trailing window, map to `0.0` and log
+`tracing::info!("trailing ... percentile unavailable: {err}")`. This is conservative
+and leaves the bypass lane (`source_count >= 2`) unaffected.
+
+Gate results
+------------
+- `cargo test --workspace --no-fail-fast`
+  - 97 tests passed, 0 failed (baseline 89; +8 new regression/unit tests)
+- `cargo fmt --all --check`
+  - exit 0
+- `cargo clippy --workspace --all-targets -- -D warnings`
+  - exit 0
+- `cd crates/news-web && trunk build --release`
+  - exit 0
+
+Files with the substantive fixes
+--------------------------------
+- crates/news-store/src/percentile.rs
+- crates/news-server/src/scheduler/cycle.rs
+- crates/news-server/src/api/stories.rs
+- crates/news-server/src/api/stories/tests.rs
+- crates/news-cli/src/replay.rs
+- crates/news-web/src/api.rs
+- crates/news-web/src/story_list.rs
+
+Git note
+--------
+The substantive fixes were already committed in the initial commit (`20a6c26`).
+This session's only code delta is the formatting commit `676a0b7` (auto-committed
+as "Updating" while running the tool pipeline).

.omo/notepads/news-triage/decisions.md

@@ -188,3 +188,24 @@ _Auto-scaffolded by /start-work. Append new entries below - never overwrite._
   DB column — a direct hand-written match keeps the DB layer decoupled
   from `news_core`'s serde attribute and makes the two directions
   symmetric and easy to audit).
+
+## F2/F3 final-wave fixes — cold-start percentile rule
+
+- **Cold-start rule for trailing-window percentile ranks**: the draft specifies
+  a cold-start fallback only for the relevance *score* (BM25-only until 20
+  feedback samples; `.omo/drafts/news-triage.md:45`), not for percentile ranks.
+  When `PercentileTracker::percentile_rank` returns `StoreError::InsufficientData`
+  because the trailing 7-day window is empty, the scheduler maps it to `0.0`
+  with a one-line `tracing::info!` log.
+- **Rationale**: conservative gate behavior. With percentile ranks at 0.0, no
+  story can meet the notify threshold (relevance @ p90) or digest band
+  [75, 90) until the window has data, preventing bogus batch-local
+  percentiles from driving decisions. The breaking-news bypass lane
+  (`source_count >= 2` or importance @ p99) is unaffected: corroboration bypass
+  is percentile-independent, and the importance percentile uses its own
+  distribution.
+- **JSON boundary for blocklist veto**: `StoryRow.relevance` is `Option<f64>`,
+  mapped with `relevance.is_finite().then_some(relevance)`. This keeps the
+  `f64::NEG_INFINITY` sentinel inside the backend scorer while serializing
+  honestly as JSON `null` at the API boundary. `importance` remains `f64`
+  because it is finite by construction (multi-hot arithmetic, no veto path).

.omo/notepads/news-triage/learnings.md

@@ -664,3 +664,24 @@ Key gotchas that would otherwise silently corrupt the index:
 
 - **Do not auto-apply snippets**. The README is operator-facing; the QA used
   scratch copies in `/tmp/opencode`. No real estate file was touched.
+
+## F2/F3 final-wave fixes
+
+- **Trailing-window percentile ranks must live in one place**: the original
+  batch-local `percentile_rank` helper was duplicated across `cycle.rs`,
+  `api/stories.rs`, and `news-cli/src/replay.rs`. Centralizing it in
+  `news-store::PercentileTracker::percentile_rank` removes the duplication and
+  guarantees the scheduler, API, and replay harness all rank against the same
+  trailing-7-day distribution.
+- **Use a stable empirical-CDF formula**: `(below * 100 + equal * 50) / count`
+  (implemented via `f64::mul_add`) avoids the small floating-point drift that
+  `(below + equal / 2.0) / count * 100.0` introduces for values like 5.5/10.
+- **Model non-finite f64 honestly at the JSON boundary**: the backend keeps
+  `f64::NEG_INFINITY` as the blocklist-veto sentinel, but the API serializes it
+  as `null` by making `StoryRow.relevance` an `Option<f64>` mapped with
+  `is_finite().then_some(...)`. The frontend mirrors the option and renders
+  `—` so the entire story list no longer fails when a blocklisted item is
+  present.
+- **Host-target tests for the frontend DTO are viable**: `news-web` can host-run
+  small `serde_json::from_str` regression tests because they only exercise the
+  `serde`-derived DTOs and do not depend on `gloo-net` or Leptos runtime APIs.

.omo/run-continuation/ses_fa0f22fcaffelGhy6E2TAbA6IS.json

@@ -0,0 +1,10 @@
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+      "updatedAt": "2026-09-01T22:41:07.513Z"
+    }
+  }
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.omo/run-continuation/ses_fa68cd6a7ffey9dPiMrqx8nxlG.json

@@ -1,10 +1,10 @@
 {
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 }