feat: Complete import functionality with RRULE fixes and comprehensive testing

- Fix RRULE BYDAY filtering for daily frequency events (Tether sync weekdays only)
- Fix timezone transfer in recurring event expansion
- Add comprehensive timezone-aware iCal generation
- Add extensive test suite for recurrence and timezone functionality
- Update dependencies and configuration examples
- Implement cleanup logic for orphaned events
- Add detailed import plan documentation

This completes the core import functionality with proper timezone handling,
RRULE parsing, and duplicate prevention mechanisms.

test_rrule.rs

@@ -0,0 +1,31 @@
+use rrule::{RRuleSet};
+use chrono::{DateTime, Utc};
+
+fn main() {
+    let rrule_str = "FREQ=WEEKLY;BYDAY=MO,WE,FR;COUNT=10";
+    println!("Testing RRULE: {}", rrule_str);
+    
+    // Test different approaches
+    match RRuleSet::from_str(rrule_str) {
+        Ok(rrule_set) => {
+            println!("Successfully parsed RRULE");
+            
+            // Check available methods
+            let start = Utc::now();
+            let end = start + chrono::Duration::days(30);
+            
+            // Try the between method
+            match rrule_set.between(start, end, true) {
+                Ok(occurrences) => {
+                    println!("Found {} occurrences", occurrences.len());
+                }
+                Err(e) => {
+                    println!("Error calling between: {}", e);
+                }
+            }
+        }
+        Err(e) => {
+            println!("Error parsing RRULE: {}", e);
+        }
+    }
+}