date mismatch fix

adr/0003-stream-bar-date-sync.md

@@ -0,0 +1,40 @@
+# ADR-0003: Stream bar date synchronization on external navigation
+
+**Date:** 2026-03-25  
+**Status:** Accepted  
+**Affects:** `StreamsBarComponent.ts`
+
+## Context
+
+The stream bar displays the currently viewed date and provides calendar navigation within a stream. When a user opens a stream file via the plugin (ribbon icon, command palette, calendar click), the plugin explicitly calls `DateStateManager.setCurrentDate()` as part of the `openStreamDate()` flow, keeping the bar in sync.
+
+However, users can also navigate to stream files through **external** means:
+
+- Clicking a file in the file explorer
+- Following an internal link from another note
+- Using Obsidian's Quick Switcher
+- Navigating browser history (back/forward)
+
+In these cases, the plugin's `openStreamDate()` is never called. The `StreamsBarComponent`'s `file-open` handler detected the correct stream via `updateStreamContext()`, but **never extracted the date from the filename**. This left the stream bar showing a stale date from whatever was previously viewed.
+
+## Decision
+
+`updateStreamContext()` now always extracts the date from the opened file's basename when the file is identified as belonging to a stream. The date is parsed from the `YYYY-MM-DD` prefix pattern and pushed to `DateStateManager.setCurrentDate()`.
+
+```typescript
+// Extract date from filename (e.g., "2026-03-25" from "2026-03-25.md")
+const match = file.basename.match(/^\d{4}-\d{2}-\d{2}/);
+if (match) {
+    const [year, month, day] = match[0].split('-').map(n => parseInt(n, 10));
+    this.dateStateManager.setCurrentDate(new Date(year, month - 1, day));
+}
+```
+
+This runs on every `file-open` event where the file matches a stream, regardless of how the navigation was initiated.
+
+## Consequences
+
+- **Stream bar stays in sync** regardless of how the user navigated to the file.
+- **Calendar highlights the correct date**, enabling adjacent-day navigation from the right starting point.
+- **No redundant updates** — `DateStateManager` already deduplicates if the date hasn't changed, so plugin-initiated navigation (which also calls `setCurrentDate`) does not cause double renders.
+- **Assumes `YYYY-MM-DD` prefix** in filenames. Files that belong to a stream folder but don't follow this naming convention will not update the date display.

src/slices/calendar-navigation/StreamsBarComponent.ts

@@ -189,6 +189,20 @@ export class StreamsBarComponent extends Component {
             if (this.selectedStream?.id !== stream.id) {
                 this.updateActiveStream(stream);
             }
+
+            // Always update the date from the filename so the bar shows the correct
+            // date even when navigating to a stream file from outside the plugin
+            if (file) {
+                const match = file.basename.match(/^\d{4}-\d{2}-\d{2}/);
+                if (match) {
+                    const [year, month, day] = match[0].split('-').map(n => parseInt(n, 10));
+                    const date = new Date(year, month - 1, day);
+                    if (!isNaN(date.getTime())) {
+                        this.dateStateManager.setCurrentDate(date);
+                    }
+                }
+            }
+
             this.component.show();
         } else {
             // If no stream found for file, hide the component