Add Boolean param kind that is always present true/false (ticket 018)

MetricPrimitiveKind gains Boolean, serialized as "boolean". A param
declared with kind Boolean skips capture-group validation and, instead
of being omitted when message_match_regex doesn't match, is present on
every log line as true/false based purely on whether the regex matches
(case-insensitively or per the regex's own flags). Params.tsx lets you
pick boolean as a kind and disables the now-unused capture group input.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01XFUNZwCvz3kcod3352ZR2o

src/profile.rs

@@ -30,6 +30,8 @@ pub enum ProfileMetricPrimitiveKind {
     Timestamp,
     /// Mirrors `MetricPrimitiveKind::Duration`.
     Duration,
+    /// Mirrors `MetricPrimitiveKind::Boolean`.
+    Boolean,
 }
 
 impl From<MetricPrimitiveKind> for ProfileMetricPrimitiveKind {
@@ -39,6 +41,7 @@ impl From<MetricPrimitiveKind> for ProfileMetricPrimitiveKind {
             MetricPrimitiveKind::Number => ProfileMetricPrimitiveKind::Number,
             MetricPrimitiveKind::Timestamp => ProfileMetricPrimitiveKind::Timestamp,
             MetricPrimitiveKind::Duration => ProfileMetricPrimitiveKind::Duration,
+            MetricPrimitiveKind::Boolean => ProfileMetricPrimitiveKind::Boolean,
         }
     }
 }
@@ -50,6 +53,7 @@ impl From<ProfileMetricPrimitiveKind> for MetricPrimitiveKind {
             ProfileMetricPrimitiveKind::Number => MetricPrimitiveKind::Number,
             ProfileMetricPrimitiveKind::Timestamp => MetricPrimitiveKind::Timestamp,
             ProfileMetricPrimitiveKind::Duration => MetricPrimitiveKind::Duration,
+            ProfileMetricPrimitiveKind::Boolean => MetricPrimitiveKind::Boolean,
         }
     }
 }