chore: remove all VectorBT references — raptorbt stands on its own

- README: remove VectorBT Comparison section and TOC entry, rewrite
  Overview/Performance as standalone benchmarks, clean metric-mapping
  table reference, update feature list to 7 strategy types including tick
- Cargo.toml / pyproject.toml: rewrite description without VectorBT mention
- __init__.py: rewrite module docstring without comparative framing
- Rust comments (engine.rs, position.rs, signals/processor.rs, core/types.rs,
  python/bindings.rs): replace "matching VectorBT behavior/formula/methodology"
  with plain descriptions of what the code does

Co-Authored-By: porcelaincode <contact@alphabench.in>

src/core/types.rs

@@ -473,7 +473,7 @@ pub struct Position {
     pub highest_since_entry: Price,
     /// Lowest price since entry (for trailing stops).
     pub lowest_since_entry: Price,
-    /// Entry fees (to include in trade PnL like VectorBT).
+    /// Entry fees included in trade PnL.
     pub entry_fees: f64,
 }
 

src/portfolio/engine.rs

@@ -237,8 +237,8 @@ impl PortfolioEngine {
                     .map(|cap| cap.min(cash))
                     .unwrap_or(cash);
 
-                // VectorBT formula: size = cash / (price * (1 + fees))
-                // This ensures the position value plus entry fee equals available cash
+                // Position sizing: size = cash / (price * (1 + fees))
+                // Ensures position value plus entry fee equals available cash
                 let fee_rate = self.config.fees;
                 let raw_size = if let Some(ref sizes) = signals.position_sizes {
                     sizes[i] * available / (adjusted_price * (1.0 + fee_rate))
@@ -299,12 +299,11 @@ impl PortfolioEngine {
             }
         }
 
-        // Mark any open position at end of data (no exit fees, matching VectorBT behavior)
+        // Mark any open position at end of data — marked-to-market, no exit fees
         if position.is_in_position() {
             let last_idx = n - 1;
             let exit_price = ohlcv.close[last_idx];
-            // No exit fees for EndOfData - position is marked-to-market but not actually closed
-            // This matches VectorBT's behavior for "Open" trades
+            // No exit fees for EndOfData: position is marked-to-market but not actually closed
             let exit_fees = 0.0;
 
             if let Some(trade) = position.close_position(
@@ -572,11 +571,9 @@ impl PortfolioEngine {
         };
 
         // Risk-adjusted metrics (calculated from daily portfolio returns, not trade returns)
-        // This matches VectorBT's calculation methodology
         let (sharpe_ratio, sortino_ratio, omega_ratio) = self.calculate_risk_metrics(returns);
 
         // Calmar ratio: CAGR / max drawdown
-        // VectorBT uses Compound Annual Growth Rate (CAGR)
         let num_periods = equity_curve.len().max(1) as f64;
         let years = num_periods / 365.25; // Convert to years using 365.25 days
         let total_return_frac = total_return_pct / 100.0;
@@ -693,13 +690,13 @@ impl PortfolioEngine {
 
     /// Calculate risk-adjusted metrics from daily portfolio returns.
     /// Returns (sharpe_ratio, sortino_ratio, omega_ratio).
-    /// Uses 365 days for annualization to match VectorBT.
+    /// Uses 365 calendar days for annualization.
     fn calculate_risk_metrics(&self, returns: &[f64]) -> (f64, f64, f64) {
         if returns.len() < 2 {
             return (0.0, 0.0, 1.0);
         }
 
-        // VectorBT uses 365 days (calendar days) for annualization
+        // 365 calendar days for annualization
         let periods_per_year: f64 = 365.0;
         let _n = returns.len() as f64;
 

src/portfolio/position.rs

@@ -112,7 +112,7 @@ impl PositionManager {
         let pos = &self.position;
         let multiplier = pos.direction.multiplier();
 
-        // Calculate P&L (matching VectorBT: gross - entry_fees - exit_fees)
+        // Calculate P&L: gross - entry_fees - exit_fees
         let gross_pnl = (exit_price - pos.entry_price) * pos.size * multiplier;
         let total_fees = pos.entry_fees + exit_fees;
         let pnl = gross_pnl - total_fees;

src/python/bindings.rs

@@ -435,7 +435,7 @@ impl PyBacktestMetrics {
         )
     }
 
-    /// Convert to dictionary matching VectorBT stats() format.
+    /// Convert to dictionary of all metrics.
     fn to_dict(&self, py: Python) -> PyResult<PyObject> {
         let dict = pyo3::types::PyDict::new(py);
         dict.set_item("Start Value", self.start_value)?;

src/signals/processor.rs

@@ -35,14 +35,13 @@ impl SignalProcessor {
 
     /// Clean entry/exit signals to ensure proper alternation.
     ///
-    /// Rules (matching VectorBT behavior):
+    /// Rules:
     /// 1. First signal must be an entry
     /// 2. After an entry, ignore further entries (unless pyramiding)
     /// 3. After an exit, ignore further exits
     /// 4. Entries and exits must alternate properly
     /// 5. Same-bar conflict: If both entry AND exit signals are True on the same bar
-    ///    when in position, VectorBT stays in position (ignores the exit).
-    ///    This matches VectorBT's "entry takes priority" behavior.
+    ///    when in position, entry takes priority — stay in position (ignore the exit).
     ///
     /// # Arguments
     /// * `entries` - Raw entry signals
@@ -75,8 +74,7 @@ impl SignalProcessor {
                 // Ignore exits when not in position
             } else {
                 // In position - looking for exit (or pyramid entry)
-                // VectorBT behavior: If both entry and exit are True, stay in position
-                // (entry signal "cancels" the exit signal)
+                // Same-bar conflict: entry takes priority — stay in position
                 if exits[i] && !entries[i] {
                     // Only exit if there's no conflicting entry signal
                     clean_exits[i] = true;