refactor(events): record tool capabilities on the invocation event

Capability is the canonical signal the plane-2 gates dispatch on, but
ToolInvocationRequestedEvent only carried the tool name — so ReadFilesProjection
classified reads by a hardcoded "file_read" string, bypassing the abstraction and
(worse) re-deriving a semantic fact at replay from whatever the name meant. That
violates the event-sourcing invariant that replay reads recorded facts, not live
state.

Now the tool's requiredCapabilities are recorded on the event at emission, and the
projection classifies by ToolCapability.FILE_READ. To let the lowest module carry
it, ToolCapability moves from core:tools into core:events keeping its package, so
every existing import resolves unchanged and core:tools imports it from below. The
field is defaulted, so pre-existing events deserialize as empty.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

core/kernel/src/main/kotlin/com/correx/core/kernel/orchestration/SessionOrchestrator.kt

@@ -648,6 +648,7 @@ abstract class SessionOrchestrator(
                     toolName = toolCall.function.name,
                     tier = tier,
                     request = request,
+                    capabilities = tool?.requiredCapabilities ?: emptySet(),
                 ),
             )
             if (toolCall.function.name != STAGE_COMPLETE_TOOL &&