feat(engine): 14-day daily-challenge calendar in the Profile modal

The daily challenge already updated streak counters, but past
completions were invisible — the player had no in-game surface to
see streak length or the actual day-by-day record. Adds a 14-dot
horizontal calendar above the Profile modal's achievements section
with a "Current streak: N · Longest: M" caption.

Each dot represents a day in the trailing 14-day window ending
today. Today's dot gets a 2-px Balatro-yellow ring; completed days
fill STATE_SUCCESS; missed days fill BG_ELEVATED. Geometry: 14 ×
12 px + 13 × 6 px gap ≈ 246 px — fits comfortably inside the
modal's 360 px min_width even on the 800 px window minimum.

PlayerProgress gains two #[serde(default)] fields:
- daily_challenge_history: Vec<NaiveDate> capped at 365 entries
  (one year of history; older entries pushed off when the cap is
  hit). Sorted ascending, deduped on insert so same-day re-runs
  don't bloat the list.
- daily_challenge_longest_streak: u32, updated whenever streak
  exceeds the previous max.

Legacy progress.json files load to empty/0 via #[serde(default)].

solitaire_sync::merge unions histories from local + remote (sorted,
capped) and takes max(longest_streak), with a clamp to ensure
longest is never below the merged current streak — guards against
legacy payloads where longest=0 but current is mid-streak.

13 new tests across solitaire_sync (record_daily history append,
chronological order, dedupe, cap, longest update, merge union,
merge cap, max longest, clamp), solitaire_data (history append,
longest update, legacy deserialise), and solitaire_engine
(modal renders 14 dots, today marker on rightmost only).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

solitaire_data/src/progress.rs

@@ -298,4 +298,70 @@ mod tests {
         assert!(!recorded_again, "same-day completion must report no-op");
         assert_eq!(p.daily_challenge_streak, 1);
     }
+
+    // --- Daily challenge history & longest streak ---
+
+    #[test]
+    fn record_daily_completion_appends_to_history() {
+        // Recording a completion adds the date to history, preserving the
+        // pre-call length + 1, and the new entry is the chronological tail.
+        let mut p = PlayerProgress::default();
+        let prev_len = p.daily_challenge_history.len();
+        let today = NaiveDate::from_ymd_opt(2026, 5, 5).unwrap();
+        let recorded = p.record_daily_completion(today);
+        assert!(recorded);
+        assert_eq!(p.daily_challenge_history.len(), prev_len + 1);
+        assert_eq!(p.daily_challenge_history.last().copied(), Some(today));
+    }
+
+    #[test]
+    fn record_daily_completion_updates_longest_streak() {
+        // A streak of 4 must lift `daily_challenge_longest_streak` from 2 to 4
+        // (we seed the previous best at 2 and watch it get overtaken).
+        let mut p = PlayerProgress {
+            daily_challenge_longest_streak: 2,
+            ..Default::default()
+        };
+        let d = NaiveDate::from_ymd_opt(2026, 5, 1).unwrap();
+        p.record_daily_completion(d);
+        p.record_daily_completion(d + Duration::days(1));
+        p.record_daily_completion(d + Duration::days(2));
+        // 3rd consecutive day equals the previous best; longest should match.
+        assert_eq!(p.daily_challenge_streak, 3);
+        assert_eq!(p.daily_challenge_longest_streak, 3);
+        // 4th consecutive day overtakes the previous best.
+        p.record_daily_completion(d + Duration::days(3));
+        assert_eq!(p.daily_challenge_streak, 4);
+        assert_eq!(p.daily_challenge_longest_streak, 4);
+    }
+
+    #[test]
+    fn legacy_progress_without_history_deserializes_to_empty() {
+        // A progress.json file produced before the history fields existed
+        // must still round-trip through serde::from_slice without error,
+        // with the new fields landing on their `#[serde(default)]` values.
+        let path = tmp_path("legacy_no_history");
+        let _ = fs::remove_file(&path);
+        let legacy_json = br#"{
+            "total_xp": 1500,
+            "level": 3,
+            "daily_challenge_last_completed": null,
+            "daily_challenge_streak": 0,
+            "weekly_goal_progress": {},
+            "unlocked_card_backs": [0],
+            "unlocked_backgrounds": [0],
+            "last_modified": "2026-04-29T12:00:00Z"
+        }"#;
+        fs::write(&path, legacy_json).expect("write");
+        let p = load_progress_from(&path);
+        assert_eq!(p.total_xp, 1500);
+        assert!(
+            p.daily_challenge_history.is_empty(),
+            "legacy file lacking daily_challenge_history must default to empty"
+        );
+        assert_eq!(
+            p.daily_challenge_longest_streak, 0,
+            "legacy file lacking daily_challenge_longest_streak must default to 0"
+        );
+    }
 }

solitaire_engine/src/profile_plugin.rs

@@ -6,6 +6,7 @@
 
 use bevy::input::ButtonInput;
 use bevy::prelude::*;
+use chrono::{Duration, Local, NaiveDate};
 use solitaire_core::achievement::achievement_by_id;
 use solitaire_data::SyncBackend;
 
@@ -20,14 +21,38 @@ use crate::ui_modal::{
     spawn_modal, spawn_modal_actions, spawn_modal_button, spawn_modal_header, ButtonVariant,
 };
 use crate::ui_theme::{
-    ACCENT_PRIMARY, STATE_INFO, STATE_SUCCESS, TEXT_PRIMARY, TEXT_SECONDARY, TYPE_BODY,
+    ACCENT_PRIMARY, BG_ELEVATED, BORDER_STRONG, SPACE_1, STATE_INFO, STATE_SUCCESS, TEXT_PRIMARY,
-    TYPE_BODY_LG, VAL_SPACE_2, Z_MODAL_PANEL,
+    TEXT_SECONDARY, TYPE_BODY, TYPE_BODY_LG, TYPE_CAPTION, VAL_SPACE_1, VAL_SPACE_2, Z_MODAL_PANEL,
 };
 
+/// Number of days surfaced in the daily-challenge calendar row.
+///
+/// 14 = trailing two weeks ending today. At ~12 px per dot with a 6 px gap
+/// the row is ~246 px wide — well inside the 360 px minimum modal width on
+/// the smallest supported window (800 px).
+const CALENDAR_DAYS: usize = 14;
+
+/// Diameter of each calendar dot, in pixels.
+const CALENDAR_DOT_SIZE_PX: f32 = 12.0;
+
 /// Marker component on the profile overlay root node.
 #[derive(Component, Debug)]
 pub struct ProfileScreen;
 
+/// Marker on each daily-challenge calendar dot inside the Profile modal.
+///
+/// One entity per day in the trailing 14-day window — tests can query
+/// for this component to assert the row was rendered.
+#[derive(Component, Debug, Clone, Copy)]
+pub struct DailyCalendarDot {
+    /// The calendar date this dot represents.
+    pub date: NaiveDate,
+    /// Whether the player completed the daily challenge on `date`.
+    pub completed: bool,
+    /// `true` if `date == today` (the rightmost dot).
+    pub is_today: bool,
+}
+
 /// Registers the `P` key toggle for the profile overlay.
 pub struct ProfilePlugin;
 
@@ -195,6 +220,16 @@ fn spawn_profile_screen(
                 font_row.clone(),
                 TextColor(TEXT_PRIMARY),
             ));
+
+            // 14-day daily-challenge calendar row.
+            spawn_daily_calendar(
+                card,
+                &prog.daily_challenge_history,
+                prog.daily_challenge_streak,
+                prog.daily_challenge_longest_streak,
+                Local::now().date_naive(),
+                font_res,
+            );
         }
 
         // ── Achievements section ────────────────────────────────────
@@ -300,6 +335,98 @@ fn spawn_spacer(parent: &mut ChildSpawnerCommands, height: Val) {
     });
 }
 
+/// Spawn the daily-challenge calendar row: a caption + 14 dots.
+///
+/// `history` is the player's full chronological completion history.
+/// `current_streak` and `longest_streak` are surfaced in the caption.
+/// `today` is passed in (rather than read directly) so the function is
+/// trivially testable with a fixed reference date.
+///
+/// Layout: caption row → row of 14 dots (~12 px each, 6 px gap). The
+/// rightmost dot represents today; past dots fill from oldest (left) to
+/// most recent (right). Each dot carries a [`DailyCalendarDot`] marker.
+fn spawn_daily_calendar(
+    parent: &mut ChildSpawnerCommands,
+    history: &[NaiveDate],
+    current_streak: u32,
+    longest_streak: u32,
+    today: NaiveDate,
+    font_res: Option<&FontResource>,
+) {
+    use std::collections::HashSet;
+    let history_set: HashSet<NaiveDate> = history.iter().copied().collect();
+
+    let font_caption = TextFont {
+        font: font_res.map(|f| f.0.clone()).unwrap_or_default(),
+        font_size: TYPE_CAPTION,
+        ..default()
+    };
+
+    parent.spawn((
+        Text::new(format!(
+            "Current streak: {current_streak}  \u{00B7}  Longest: {longest_streak}"
+        )),
+        font_caption,
+        TextColor(TEXT_SECONDARY),
+        Node {
+            margin: UiRect {
+                top: VAL_SPACE_1,
+                bottom: VAL_SPACE_1,
+                ..default()
+            },
+            ..default()
+        },
+    ));
+
+    parent
+        .spawn(Node {
+            flex_direction: FlexDirection::Row,
+            column_gap: Val::Px(SPACE_1 + 2.0), // 6 px between dots
+            align_items: AlignItems::Center,
+            ..default()
+        })
+        .with_children(|row| {
+            // Iterate from oldest (today − 13) to today (rightmost).
+            for offset in (0..CALENDAR_DAYS as i64).rev() {
+                let date = today - Duration::days(offset);
+                let is_today = offset == 0;
+                let completed = history_set.contains(&date);
+                // Today's dot keeps the outlined-ring look (Balatro-yellow
+                // accent border) regardless of completion; past days use a
+                // subtle border so the row reads as a row of pills, not a
+                // strip of bare squares.
+                let border_color = if is_today { ACCENT_PRIMARY } else { BORDER_STRONG };
+                let border_width = if is_today { 2.0 } else { 0.0 };
+                row.spawn((
+                    DailyCalendarDot {
+                        date,
+                        completed,
+                        is_today,
+                    },
+                    Node {
+                        width: Val::Px(CALENDAR_DOT_SIZE_PX),
+                        height: Val::Px(CALENDAR_DOT_SIZE_PX),
+                        border: UiRect::all(Val::Px(border_width)),
+                        border_radius: BorderRadius::all(Val::Px(CALENDAR_DOT_SIZE_PX / 2.0)),
+                        ..default()
+                    },
+                    BackgroundColor(calendar_dot_color(completed)),
+                    BorderColor::all(border_color),
+                ));
+            }
+        });
+}
+
+/// Background colour for a calendar dot. `STATE_SUCCESS` for completed
+/// days, `BG_ELEVATED` for missed/pending days.
+fn calendar_dot_color(completed: bool) -> Color {
+    if completed {
+        STATE_SUCCESS
+    } else {
+        BG_ELEVATED
+    }
+}
+
 /// Return `(backend_name, username_display)` for the given sync backend.
 fn sync_info(backend: &SyncBackend) -> (&'static str, String) {
     match backend {
@@ -417,4 +544,43 @@ mod tests {
         // Level 10 is the first post-table level (span = 1000, starts at 5000).
         assert_eq!(xp_progress(5_000, 10), (1_000, 0));
     }
+
+    #[test]
+    fn profile_modal_renders_14_calendar_dots() {
+        // Open the Profile modal and assert the 14-day calendar row was
+        // populated with one DailyCalendarDot entity per day.
+        let mut app = headless_app();
+        app.world_mut()
+            .resource_mut::<ButtonInput<KeyCode>>()
+            .press(KeyCode::KeyP);
+        app.update();
+
+        let dot_count = app
+            .world_mut()
+            .query::<&DailyCalendarDot>()
+            .iter(app.world())
+            .count();
+        assert_eq!(
+            dot_count, CALENDAR_DAYS,
+            "Profile modal must render exactly {CALENDAR_DAYS} calendar dots"
+        );
+    }
+
+    #[test]
+    fn calendar_dot_today_marker_is_set_on_rightmost_dot_only() {
+        // Exactly one of the 14 dots is the "today" dot (the rightmost).
+        let mut app = headless_app();
+        app.world_mut()
+            .resource_mut::<ButtonInput<KeyCode>>()
+            .press(KeyCode::KeyP);
+        app.update();
+
+        let today_count = app
+            .world_mut()
+            .query::<&DailyCalendarDot>()
+            .iter(app.world())
+            .filter(|d| d.is_today)
+            .count();
+        assert_eq!(today_count, 1, "exactly one dot must be marked is_today");
+    }
 }

solitaire_sync/src/merge.rs

@@ -3,10 +3,10 @@
 //! All functions are free of I/O and side effects — safe to call from any
 //! context including unit tests and the Bevy main thread.
 
-use chrono::Utc;
+use chrono::{NaiveDate, Utc};
 
 use crate::{AchievementRecord, ConflictReport, PlayerProgress, StatsSnapshot, SyncPayload};
-use crate::progress::level_for_xp;
+use crate::progress::{level_for_xp, DAILY_CHALLENGE_HISTORY_CAP};
 
 /// Merge two [`SyncPayload`]s into a single authoritative result.
 ///
@@ -240,6 +240,22 @@ fn merge_progress(
     // Challenge index: take the higher (further ahead in challenge progression).
     let challenge_index = local.challenge_index.max(remote.challenge_index);
 
+    // Daily-challenge history: union the two ordered lists into a sorted,
+    // deduplicated, capped Vec so completions made on either device survive.
+    let daily_challenge_history = union_naive_dates(
+        &local.daily_challenge_history,
+        &remote.daily_challenge_history,
+    );
+
+    // Longest streak ever: simple max — never regresses.
+    let daily_challenge_longest_streak = local
+        .daily_challenge_longest_streak
+        .max(remote.daily_challenge_longest_streak)
+        // Also defend against an old payload whose `longest_streak` was
+        // never written but whose current `daily_challenge_streak` exceeds
+        // the recorded longest — keep them coherent post-merge.
+        .max(daily_challenge_streak);
+
     PlayerProgress {
         total_xp,
         level: level_for_xp(total_xp),
@@ -250,6 +266,8 @@ fn merge_progress(
         unlocked_card_backs,
         unlocked_backgrounds,
         challenge_index,
+        daily_challenge_history,
+        daily_challenge_longest_streak,
         last_modified: Utc::now(),
     }
 }
@@ -261,6 +279,20 @@ fn union_usize_vecs(a: &[usize], b: &[usize]) -> Vec<usize> {
     set.into_iter().collect()
 }
 
+/// Returns the sorted union of two `NaiveDate` slices with duplicates
+/// removed and the result capped at [`DAILY_CHALLENGE_HISTORY_CAP`]
+/// entries (oldest dates trimmed first).
+fn union_naive_dates(a: &[NaiveDate], b: &[NaiveDate]) -> Vec<NaiveDate> {
+    use std::collections::BTreeSet;
+    let set: BTreeSet<NaiveDate> = a.iter().chain(b.iter()).copied().collect();
+    let mut v: Vec<NaiveDate> = set.into_iter().collect();
+    if v.len() > DAILY_CHALLENGE_HISTORY_CAP {
+        let excess = v.len() - DAILY_CHALLENGE_HISTORY_CAP;
+        v.drain(0..excess);
+    }
+    v
+}
+
 // ---------------------------------------------------------------------------
 // Tests
 // ---------------------------------------------------------------------------
@@ -753,4 +785,110 @@ mod tests {
         let (merged, _) = merge(&local, &remote);
         assert_eq!(merged.stats.fastest_win_seconds, 300);
     }
+
+    // -----------------------------------------------------------------------
+    // Daily-challenge history + longest-streak merge
+    // -----------------------------------------------------------------------
+
+    fn nd(y: i32, m: u32, d: u32) -> NaiveDate {
+        NaiveDate::from_ymd_opt(y, m, d).unwrap()
+    }
+
+    #[test]
+    fn merge_unions_daily_challenge_history() {
+        // Local and remote have disjoint completion dates; the merged
+        // history must contain all of them, sorted ascending, with no
+        // duplicates and within the cap.
+        let mut local = default_payload();
+        local.progress.daily_challenge_history =
+            vec![nd(2026, 4, 20), nd(2026, 4, 22), nd(2026, 4, 24)];
+        let mut remote = default_payload();
+        remote.progress.daily_challenge_history =
+            vec![nd(2026, 4, 21), nd(2026, 4, 22), nd(2026, 4, 25)];
+
+        let (merged, _) = merge(&local, &remote);
+        assert_eq!(
+            merged.progress.daily_challenge_history,
+            vec![
+                nd(2026, 4, 20),
+                nd(2026, 4, 21),
+                nd(2026, 4, 22),
+                nd(2026, 4, 24),
+                nd(2026, 4, 25),
+            ],
+            "history union must be sorted, deduplicated, and contain every date from either side"
+        );
+        assert!(
+            merged.progress.daily_challenge_history.len() <= DAILY_CHALLENGE_HISTORY_CAP,
+            "merged history must respect the 365-entry cap"
+        );
+    }
+
+    #[test]
+    fn merge_caps_daily_challenge_history_at_max() {
+        // Construct a local history that already has CAP entries and a
+        // remote history that adds 50 fresher entries — the merge must
+        // drop the oldest 50 so the cap is preserved.
+        let start = nd(2024, 1, 1);
+        let local_dates: Vec<NaiveDate> = (0..DAILY_CHALLENGE_HISTORY_CAP as i64)
+            .map(|i| start + chrono::Duration::days(i))
+            .collect();
+        let remote_dates: Vec<NaiveDate> = (DAILY_CHALLENGE_HISTORY_CAP as i64
+            ..DAILY_CHALLENGE_HISTORY_CAP as i64 + 50)
+            .map(|i| start + chrono::Duration::days(i))
+            .collect();
+
+        let mut local = default_payload();
+        local.progress.daily_challenge_history = local_dates.clone();
+        let mut remote = default_payload();
+        remote.progress.daily_challenge_history = remote_dates.clone();
+
+        let (merged, _) = merge(&local, &remote);
+        assert_eq!(
+            merged.progress.daily_challenge_history.len(),
+            DAILY_CHALLENGE_HISTORY_CAP,
+            "merged history must be capped at DAILY_CHALLENGE_HISTORY_CAP"
+        );
+        // The oldest 50 entries should have been evicted; oldest retained
+        // is therefore start + 50 days.
+        assert_eq!(
+            merged.progress.daily_challenge_history.first().copied(),
+            Some(start + chrono::Duration::days(50))
+        );
+        // Most recent retained is the last remote date.
+        assert_eq!(
+            merged.progress.daily_challenge_history.last().copied(),
+            remote_dates.last().copied()
+        );
+    }
+
+    #[test]
+    fn merge_takes_max_longest_streak() {
+        let mut local = default_payload();
+        local.progress.daily_challenge_longest_streak = 4;
+        let mut remote = default_payload();
+        remote.progress.daily_challenge_longest_streak = 9;
+        let (merged, _) = merge(&local, &remote);
+        assert_eq!(
+            merged.progress.daily_challenge_longest_streak, 9,
+            "longest streak must be the max across both sides"
+        );
+    }
+
+    #[test]
+    fn merge_longest_streak_never_below_current_streak() {
+        // If a payload's `daily_challenge_longest_streak` was never written
+        // (legacy file) but its `daily_challenge_streak` is non-zero, the
+        // merged longest must reflect at least the current streak so the
+        // two values stay coherent.
+        let mut local = default_payload();
+        local.progress.daily_challenge_streak = 7;
+        local.progress.daily_challenge_longest_streak = 0; // legacy
+        let remote = default_payload();
+        let (merged, _) = merge(&local, &remote);
+        assert!(
+            merged.progress.daily_challenge_longest_streak >= 7,
+            "longest streak must be at least as large as the merged current streak"
+        );
+    }
 }

solitaire_sync/src/progress.rs

@@ -18,6 +18,13 @@ pub fn level_for_xp(xp: u64) -> u32 {
     }
 }
 
+/// Maximum number of dates retained in [`PlayerProgress::daily_challenge_history`].
+///
+/// Bounds the per-player file size across years of play. ~365 entries is
+/// roughly a year of daily completions, far more than the 14-day window the
+/// in-game calendar surfaces.
+pub const DAILY_CHALLENGE_HISTORY_CAP: usize = 365;
+
 /// Persisted player progression state.
 ///
 /// Mutation helpers such as `add_xp`, `record_daily_completion`, etc. are
@@ -45,6 +52,14 @@ pub struct PlayerProgress {
     /// Index of the next Challenge-mode seed to serve to this player.
     #[serde(default)]
     pub challenge_index: u32,
+    /// All dates the player has completed the daily challenge, in
+    /// chronological ascending order. Bounded to the most recent 365
+    /// entries so file size stays bounded across years of play.
+    #[serde(default)]
+    pub daily_challenge_history: Vec<NaiveDate>,
+    /// Longest daily-challenge streak ever achieved on this profile.
+    #[serde(default)]
+    pub daily_challenge_longest_streak: u32,
     /// Wall-clock time of the last modification (used for conflict detection).
     pub last_modified: DateTime<Utc>,
 }
@@ -61,6 +76,8 @@ impl Default for PlayerProgress {
             unlocked_card_backs: vec![0],
             unlocked_backgrounds: vec![0],
             challenge_index: 0,
+            daily_challenge_history: Vec::new(),
+            daily_challenge_longest_streak: 0,
             last_modified: DateTime::UNIX_EPOCH,
         }
     }
@@ -114,6 +131,12 @@ impl PlayerProgress {
     /// - Completion the day after the previous: streak increments.
     /// - Same day as the previous: no-op (idempotent).
     ///
+    /// On every fresh completion, `date` is appended to
+    /// `daily_challenge_history` (kept sorted ascending and capped at
+    /// [`DAILY_CHALLENGE_HISTORY_CAP`] entries) and
+    /// `daily_challenge_longest_streak` is bumped if the current streak
+    /// exceeds it.
+    ///
     /// Returns `true` if this call recorded a fresh completion.
     pub fn record_daily_completion(&mut self, date: NaiveDate) -> bool {
         match self.daily_challenge_last_completed {
@@ -126,6 +149,19 @@ impl PlayerProgress {
             }
         }
         self.daily_challenge_last_completed = Some(date);
+        // Append to history (defensive against duplicates and out-of-order
+        // dates so a hand-edited or merged file can't corrupt the order).
+        if !self.daily_challenge_history.contains(&date) {
+            self.daily_challenge_history.push(date);
+            self.daily_challenge_history.sort();
+            if self.daily_challenge_history.len() > DAILY_CHALLENGE_HISTORY_CAP {
+                let excess = self.daily_challenge_history.len() - DAILY_CHALLENGE_HISTORY_CAP;
+                self.daily_challenge_history.drain(0..excess);
+            }
+        }
+        if self.daily_challenge_streak > self.daily_challenge_longest_streak {
+            self.daily_challenge_longest_streak = self.daily_challenge_streak;
+        }
         self.last_modified = Utc::now();
         true
     }
@@ -320,4 +356,85 @@ mod tests {
         p.record_daily_completion(date(2026, 4, 22)); // skip the 21st
         assert_eq!(p.daily_challenge_streak, 1, "gap must reset streak");
     }
+
+    // -----------------------------------------------------------------------
+    // record_daily_completion — history + longest-streak side effects
+    // -----------------------------------------------------------------------
+
+    #[test]
+    fn record_daily_completion_appends_to_history_in_chronological_order() {
+        let mut p = PlayerProgress::default();
+        assert!(p.daily_challenge_history.is_empty());
+        p.record_daily_completion(date(2026, 4, 20));
+        p.record_daily_completion(date(2026, 4, 21));
+        p.record_daily_completion(date(2026, 4, 22));
+        assert_eq!(
+            p.daily_challenge_history,
+            vec![
+                date(2026, 4, 20),
+                date(2026, 4, 21),
+                date(2026, 4, 22),
+            ],
+            "history should hold all three completions in ascending order"
+        );
+    }
+
+    #[test]
+    fn record_daily_completion_same_day_does_not_duplicate_history() {
+        let mut p = PlayerProgress::default();
+        p.record_daily_completion(date(2026, 4, 20));
+        p.record_daily_completion(date(2026, 4, 20));
+        assert_eq!(
+            p.daily_challenge_history,
+            vec![date(2026, 4, 20)],
+            "same-day completion is a no-op and must not duplicate history"
+        );
+    }
+
+    #[test]
+    fn record_daily_completion_updates_longest_streak() {
+        let mut p = PlayerProgress::default();
+        // Three-day streak: longest jumps from 0 → 3.
+        p.record_daily_completion(date(2026, 4, 20));
+        p.record_daily_completion(date(2026, 4, 21));
+        p.record_daily_completion(date(2026, 4, 22));
+        assert_eq!(p.daily_challenge_streak, 3);
+        assert_eq!(p.daily_challenge_longest_streak, 3);
+
+        // Gap resets the current streak — longest must NOT regress.
+        p.record_daily_completion(date(2026, 4, 25));
+        assert_eq!(p.daily_challenge_streak, 1);
+        assert_eq!(
+            p.daily_challenge_longest_streak, 3,
+            "longest_streak must never regress after a gap"
+        );
+
+        // Two-day streak — still below longest, so longest stays at 3.
+        p.record_daily_completion(date(2026, 4, 26));
+        assert_eq!(p.daily_challenge_streak, 2);
+        assert_eq!(p.daily_challenge_longest_streak, 3);
+    }
+
+    #[test]
+    fn daily_challenge_history_is_capped_at_max() {
+        // Push DAILY_CHALLENGE_HISTORY_CAP + 5 consecutive days; the
+        // earliest five must be evicted and the most recent CAP retained.
+        let mut p = PlayerProgress::default();
+        let start = date(2024, 1, 1);
+        let total = DAILY_CHALLENGE_HISTORY_CAP + 5;
+        for offset in 0..total {
+            p.record_daily_completion(start + Duration::days(offset as i64));
+        }
+        assert_eq!(p.daily_challenge_history.len(), DAILY_CHALLENGE_HISTORY_CAP);
+        // Oldest retained is `start + 5` (we dropped the first 5).
+        assert_eq!(
+            p.daily_challenge_history.first().copied(),
+            Some(start + Duration::days(5))
+        );
+        // Newest retained is the last date pushed.
+        assert_eq!(
+            p.daily_challenge_history.last().copied(),
+            Some(start + Duration::days(total as i64 - 1))
+        );
+    }
 }