feat: move config.py to config.example.py, exclude config.py from git tracking

- Copy config.py to config.example.py as template (tracked in git)
- Add config.py to .gitignore (local config per developer)
- Update README.md with configuration setup instructions
- Fix outdated references (TinyDB -> SQLite, add missing files)
- Persist goal selection across task and note pages

static/js/notes.js

@@ -107,7 +107,7 @@ async function openNote(noteId) {
     document.getElementById("note-modal").classList.add("active");
 }
 
-function openNewNote() {
+async function openNewNote() {
     editingNoteId = null;
     document.getElementById("note-modal-title").textContent = "New Note";
     document.getElementById("note-id").value = "";
@@ -120,7 +120,11 @@ function openNewNote() {
     document.getElementById("note-modal").classList.add("active");
 
     if (savedGoalId) {
-        populateTasks(savedGoalId);
+        await populateTasks(savedGoalId);
+        const goal = goals.find(g => g.id === savedGoalId);
+        if (goal && goal.selected_task_id) {
+            document.getElementById("note-task").value = goal.selected_task_id;
+        }
     } else {
         document.getElementById("note-task").innerHTML = '<option value="">None</option>';
     }
@@ -225,10 +229,7 @@ document.addEventListener("DOMContentLoaded", () => {
         populateTasks(goalId);
     });
 
-    document.getElementById("filter-goal").addEventListener("change", async () => {
-        const goalId = parseInt(document.getElementById("filter-goal").value) || null;
-        savedGoalId = goalId;
-        await patch("/api/user/selected-goal", { goal_id: goalId });
+    document.getElementById("filter-goal").addEventListener("change", () => {
         loadNotes();
     });