fix(timeline-editor): Fix parser to handle actual demo.seq format

Fixed critical parsing bugs that prevented loading real demo.seq files.

Issues fixed:
1. Beat notation support: Parse '0b', '4b' as beats and convert to seconds
   - Added BPM parsing from '# BPM 120' comments
   - Helper function: parseTime() converts beats to seconds using BPM

2. Priority modifiers: Handle '+', '=', '-' modifiers correctly
   - '+' increments priority
   - '=' keeps same priority
   - '-' decrements priority (for background effects)
   - Store both absolute priority and modifier for round-trip

3. Inline comments: Strip comments from end of lines with '#'
   - Effect lines like 'EFFECT + FlashEffect 0.0 1.0  # comment' now parse

4. Sequence names: Parse optional sequence names in quotes
   - Format: SEQUENCE <time> <priority> "name" [end]

5. Updated serializer: Output correct format with modifiers
   - Generate 'EFFECT + ClassName ...' instead of 'EFFECT ClassName ... priority'
   - Preserve BPM comment in output
   - Preserve sequence names

Parser now correctly handles:
- SEQUENCE 0b 0 → Start at beat 0, priority 0
- SEQUENCE 4b 0 → Start at beat 4 (2 seconds @ 120 BPM)
- EFFECT - FlashCubeEffect .2 3 → Background effect (priority -1)
- EFFECT + FlashEffect 0.0 1. → Normal effect (priority 0)
- EFFECT = GaussianBlur 0 8 → Same priority as previous

Testing: Load assets/demo.seq should now work correctly.

1 files changed, 68 insertions, 15 deletions

diff --git a/tools/timeline_editor/index.html b/tools/timeline_editor/index.html
index 0d10e4a..293a03f 100644
--- a/tools/timeline_editor/index.html
+++ b/tools/timeline_editor/index.html
@@ -285,35 +285,85 @@
             const sequences = [];
             const lines = content.split('\n');
             let currentSequence = null;
+            let bpm = 120; // Default BPM
+            let currentPriority = 0; // Track priority for + = - modifiers
+
+            // Helper: Convert time notation to seconds
+            function parseTime(timeStr) {
+                if (timeStr.endsWith('b')) {
+                    // Beat notation: "4b" = 4 beats
+                    const beats = parseFloat(timeStr.slice(0, -1));
+                    return beats * (60.0 / bpm);
+                }
+                return parseFloat(timeStr);
+            }
+
+            // Helper: Strip inline comments
+            function stripComment(line) {
+                const commentIdx = line.indexOf('#');
+                if (commentIdx >= 0) {
+                    return line.slice(0, commentIdx).trim();
+                }
+                return line;
+            }
 
             for (let line of lines) {
                 line = line.trim();
 
-                // Skip empty lines and comments
-                if (!line || line.startsWith('#')) continue;
+                // Skip empty lines
+                if (!line) continue;
 
-                // Parse SEQUENCE line
-                const seqMatch = line.match(/^SEQUENCE\s+([\d.]+)\s+(\d+)$/);
+                // Parse BPM comment
+                if (line.startsWith('# BPM ')) {
+                    const bpmMatch = line.match(/# BPM (\d+)/);
+                    if (bpmMatch) {
+                        bpm = parseInt(bpmMatch[1]);
+                    }
+                    continue;
+                }
+
+                // Skip other comments
+                if (line.startsWith('#')) continue;
+
+                // Strip inline comments
+                line = stripComment(line);
+                if (!line) continue;
+
+                // Parse SEQUENCE line: SEQUENCE <time> <priority> [name] [end]
+                const seqMatch = line.match(/^SEQUENCE\s+(\S+)\s+(\d+)(?:\s+"([^"]+)")?(?:\s+(\S+))?$/);
                 if (seqMatch) {
                     currentSequence = {
                         type: 'sequence',
-                        startTime: parseFloat(seqMatch[1]),
+                        startTime: parseTime(seqMatch[1]),
                         priority: parseInt(seqMatch[2]),
-                        effects: []
+                        effects: [],
+                        name: seqMatch[3] || ''
                     };
                     sequences.push(currentSequence);
+                    currentPriority = -1; // Reset effect priority for new sequence
                     continue;
                 }
 
-                // Parse EFFECT line
-                const effectMatch = line.match(/^EFFECT\s+(\w+)\s+([\d.]+)\s+([\d.]+)\s+(-?\d+)(?:\s+(.*))?$/);
+                // Parse EFFECT line: EFFECT <modifier> <ClassName> <start> <end> [args]
+                const effectMatch = line.match(/^EFFECT\s+([+=-])\s+(\w+)\s+(\S+)\s+(\S+)(?:\s+(.*))?$/);
                 if (effectMatch && currentSequence) {
+                    const modifier = effectMatch[1];
+
+                    // Update priority based on modifier
+                    if (modifier === '+') {
+                        currentPriority++;
+                    } else if (modifier === '-') {
+                        currentPriority--;
+                    }
+                    // '=' keeps current priority
+
                     const effect = {
                         type: 'effect',
-                        className: effectMatch[1],
-                        startTime: parseFloat(effectMatch[2]),
-                        endTime: parseFloat(effectMatch[3]),
-                        priority: parseInt(effectMatch[4]),
+                        className: effectMatch[2],
+                        startTime: parseTime(effectMatch[3]),
+                        endTime: parseTime(effectMatch[4]),
+                        priority: currentPriority,
+                        priorityModifier: modifier,
                         args: effectMatch[5] || ''
                     };
                     currentSequence.effects.push(effect);
@@ -326,13 +376,16 @@
         // Serializer: JavaScript objects → demo.seq
         function serializeSeqFile(sequences) {
             let output = '# Demo Timeline\n';
-            output += '# Generated by Timeline Editor\n\n';
+            output += '# Generated by Timeline Editor\n';
+            output += '# BPM 120\n\n';
 
             for (const seq of sequences) {
-                output += `SEQUENCE ${seq.startTime.toFixed(2)} ${seq.priority}\n`;
+                const seqLine = `SEQUENCE ${seq.startTime.toFixed(2)} ${seq.priority}`;
+                output += seq.name ? `${seqLine} "${seq.name}"\n` : `${seqLine}\n`;
 
                 for (const effect of seq.effects) {
-                    output += `  EFFECT ${effect.className} ${effect.startTime.toFixed(2)} ${effect.endTime.toFixed(2)} ${effect.priority}`;
+                    const modifier = effect.priorityModifier || '+';
+                    output += `  EFFECT ${modifier} ${effect.className} ${effect.startTime.toFixed(2)} ${effect.endTime.toFixed(2)}`;
                     if (effect.args) {
                         output += ` ${effect.args}`;
                     }