feat(ai) - add observability (#20850)

**AI Chat - Tool Executions (counters, tagged with model)**
ai-chat/tool-execution-succeeded: number of tool calls invoked by the AI
that completed without error
ai-chat/tool-execution-failed: number of tool calls invoked by the AI
that threw an error
**AI Chat - Token Usage (counters, tagged with model)**
ai-chat/input-tokens: total input tokens sent to the model across all
turns
ai-chat/output-tokens: total output tokens generated by the model
ai-chat/cache-read-tokens: input tokens served from the model's prompt
cache (cheaper)
ai-chat/cache-write-tokens: input tokens written into the prompt cache
for future reuse
**AI Chat - Latency (histograms in ms, tagged with model)**
ai-chat/turn-latency-ms: total duration of a full chat turn (from stream
start to stream end)
ai-chat/step-latency-ms: duration of a single reasoning/tool-call step
within a turn
ai-chat/ttft-ms: time-to-first-token, i.e. how long until the model
starts streaming output
**MCP - Tool Executions (counters)**
mcp/tool-execution-succeeded: number of MCP tool calls that completed
successfully
mcp/tool-execution-failed: number of MCP tool calls that threw an error

packages/twenty-server/src/engine/metadata-modules/webhook/jobs/call-webhook.job.ts

@@ -95,7 +95,7 @@ export class CallWebhookJob {
         ...commonPayload,
       });
 
-      void this.metricsService.incrementCounter({
+      void this.metricsService.incrementCounterForEvent({
         key: MetricsKeys.JobWebhookCallCompleted,
         shouldStoreInCache: false,
       });