feat: always-on Insights — correlation analysis over viewing habits

Conservative, live insights (ADR-0010) derived from each user's diary:
rating lift by genre (first-time watches only), genre seasonality vs a
uniform 1/12 month baseline, medium weekend-lift, and watch-time rhythm.

- domain: WatchRow model, InsightsQuery port, pure insights_analyzer with
  all honesty thresholds (sample minimums, strength cutoffs, suppressions
  for import noise), unit-tested
- adapters: thin Sqlite/Postgres fetch twins, reusing WrapUp's genre fetch
- application: get_insights use case, InsightsGroup in Deps
- composition/server: wiring through Repositories/DatabaseOutput
- presentation: GET /api/v1/insights handler, typed serde-tagged DTOs,
  openapi doc
- spa: /insights route (shadcn cards), insights feature hook, profile
  entry link, en locale strings
- server test: end-to-end seed sqlite → HTTP → rating lift + rhythm

Also records ADR-0010, defines "Insight" in the glossary, and includes
pre-existing worktree comment-stripping cleanups.

crates/api-types/src/diary.rs

@@ -60,7 +60,6 @@ pub struct FeedEntryDto {
 #[derive(Debug, Clone, Deserialize, utoipa::IntoParams)]
 #[into_params(parameter_in = Query)]
 pub struct ExportQueryParams {
-    /// Output format: `csv` (default) or `json`
     #[serde(default = "default_export_format")]
     pub format: String,
 }

crates/api-types/src/import.rs

@@ -17,13 +17,9 @@ pub struct SessionStateResponse {
 
 #[derive(Debug, Clone, Serialize, Deserialize, utoipa::ToSchema)]
 pub struct ApiFieldMapping {
-    /// Column name in the source file
     pub source_column: String,
-    /// Domain field: title | release_year | director | rating | watched_at | comment | external_metadata_id
     pub domain_field: String,
-    /// For rating fields: multiply raw value by this factor (e.g. 0.5 for 10-point → 5-point scale)
     pub rating_scale: Option<f64>,
-    /// For watched_at fields: strftime format hint (e.g. "%d/%m/%Y")
     pub date_format: Option<String>,
 }
 
@@ -34,15 +30,12 @@ pub struct ApplyMappingRequest {
 
 #[derive(Debug, Clone, Serialize, Deserialize, utoipa::ToSchema)]
 pub struct ConfirmRequest {
-    /// Indices (0-based) of rows from the mapping preview to import
     pub confirmed_indices: Vec<usize>,
 }
 
 #[derive(Debug, Clone, Serialize, Deserialize, utoipa::ToSchema)]
 pub struct SaveProfileRequest {
-    /// Session UUID whose current field_mappings to save
     pub session_id: String,
-    /// Human-readable profile name (e.g. "Letterboxd")
     pub name: String,
 }
 

crates/api-types/src/insights.rs

@@ -0,0 +1,49 @@
+use serde::{Deserialize, Serialize};
+use utoipa::ToSchema;
+
+/// One conservative, baseline-relative statement about the user's viewing
+/// behavior. Tagged by `kind` so the SPA can switch on it; every variant
+/// carries `sample_count` so the UI can explain a thin sample.
+#[derive(Debug, Clone, Serialize, Deserialize, ToSchema)]
+#[serde(tag = "kind", rename_all = "snake_case")]
+pub enum InsightDto {
+    /// `genre`'s average rating sits `delta` stars from the user's own
+    /// average (first-time watches only).
+    RatingLift {
+        genre: String,
+        genre_avg: f64,
+        user_avg: f64,
+        delta: f64,
+        sample_count: u32,
+    },
+    /// `genre`'s share of watches in `month` (1–12) is `multiplier` times the
+    /// uniform 1/12 baseline.
+    Seasonality {
+        genre: String,
+        month: u32,
+        multiplier: f64,
+        sample_count: u32,
+    },
+    /// `medium`'s weekend share of watches is `multiplier` times the user's
+    /// overall weekend share.
+    MediumTiming {
+        medium: String,
+        multiplier: f64,
+        weekend_share: f64,
+        baseline_share: f64,
+        sample_count: u32,
+    },
+    /// Watching concentrates in a 3-hour window starting `peak_hour_start`
+    /// (0–23) on `top_days` (Mon=1 … Sun=7).
+    Rhythm {
+        peak_hour_start: u32,
+        peak_hour_end: u32,
+        top_days: Vec<u32>,
+        sample_count: u32,
+    },
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize, ToSchema)]
+pub struct InsightsResponse {
+    pub insights: Vec<InsightDto>,
+}

crates/api-types/src/lib.rs

@@ -3,6 +3,7 @@ pub mod common;
 pub mod diary;
 pub mod goals;
 pub mod import;
+pub mod insights;
 pub mod movies;
 pub mod rendering;
 pub mod search;
@@ -17,6 +18,7 @@ pub use common::*;
 pub use diary::*;
 pub use goals::*;
 pub use import::*;
+pub use insights::*;
 pub use movies::*;
 pub use rendering::*;
 pub use social::*;

crates/api-types/src/movies.rs

@@ -10,11 +10,8 @@ use crate::common::SocialFeedResponse;
 pub struct MoviesQueryParams {
     pub limit: Option<u32>,
     pub offset: Option<u32>,
-    /// Optional title filter (case-insensitive substring match)
     pub search: Option<String>,
-    /// Filter by genre name (case-insensitive)
     pub genre: Option<String>,
-    /// Filter by ISO language code (e.g. "en")
     pub language: Option<String>,
 }
 

crates/api-types/src/search.rs

@@ -6,21 +6,13 @@ pub use crate::common::{PaginatedMovieHits, PaginatedPersonHits};
 
 #[derive(Debug, Deserialize, IntoParams)]
 pub struct SearchQueryParams {
-    /// Free-text query matched across title, cast, crew, genres and keywords.
     pub q: Option<String>,
-    /// Filter by genre name (exact match, case-sensitive).
     pub genre: Option<String>,
-    /// Filter by release year.
     pub year: Option<u16>,
-    /// Filter by person ID (UUID).
     pub person_id: Option<Uuid>,
-    /// Filter crew results by department (e.g. "Directing", "Writing").
     pub department: Option<String>,
-    /// Filter by original language code (e.g. "en", "fr").
     pub language: Option<String>,
-    /// Max results to return (default 20).
     pub limit: Option<u32>,
-    /// Offset for pagination (default 0).
     pub offset: Option<u32>,
 }
 

crates/api-types/src/social.rs

@@ -16,7 +16,6 @@ pub struct RemoteActorDto {
     pub handle: String,
     pub display_name: Option<String>,
     pub url: String,
-    /// `Some` for local actors, so the SPA can link internally to `/users/{id}`.
     pub user_id: Option<Uuid>,
     pub avatar_url: Option<String>,
 }
@@ -79,12 +78,11 @@ pub struct PendingCountResponse {
     pub count: usize,
 }
 
+//todo: move out to separate file
 #[cfg(test)]
 mod tests {
     use super::*;
 
-    /// Task 7's SPA zod schema parses these exact lowercase literals —
-    /// a casing or naming drift here breaks the SPA at runtime.
     #[test]
     fn follow_state_dto_serializes_to_lowercase_strings() {
         assert_eq!(

crates/api-types/src/users.rs

@@ -23,7 +23,6 @@ pub struct UsersResponse {
 #[derive(Debug, Clone, Deserialize, utoipa::IntoParams)]
 #[into_params(parameter_in = Query)]
 pub struct UserProfileQueryParams {
-    /// One of: `recent` (default), `ratings`, `history`, `trends`
     pub view: Option<String>,
     pub limit: Option<u32>,
     pub offset: Option<u32>,