fix(core): Set op on ended Vercel AI spans

[RulaKhaled]

Ensures Vercel AI span op is always set correctly at span start, regardless of whether the model ID is available.

Changes:

• Removed the model ID check gate before calling processGenerateSpan - the op is determined by span name, not model ID
• Span name updates (e.g., generate_text gpt-4) are now only applied when model ID exists, avoiding undefined in names
• Added integration test for late model ID scenario

Closes #18448

[linear]

JS-1280 vercelAIIntegration: span op stays 'default' instead of 'gen_ai.invoke_agent' - AI Agents dashboard shows no data

[github-actions]

size-limit report 📦

Path	Size	% Change	Change
@sentry/browser	24.82 kB	-	-
@sentry/browser - with treeshaking flags	23.32 kB	-	-
@sentry/browser (incl. Tracing)	41.6 kB	-	-
@sentry/browser (incl. Tracing, Profiling)	46.19 kB	-	-
@sentry/browser (incl. Tracing, Replay)	80.17 kB	-	-
@sentry/browser (incl. Tracing, Replay) - with treeshaking flags	69.91 kB	-	-
@sentry/browser (incl. Tracing, Replay with Canvas)	84.85 kB	-	-
@sentry/browser (incl. Tracing, Replay, Feedback)	97.1 kB	-	-
@sentry/browser (incl. Feedback)	41.54 kB	-	-
@sentry/browser (incl. sendFeedback)	29.51 kB	-	-
@sentry/browser (incl. FeedbackAsync)	34.5 kB	-	-
@sentry/browser (incl. Metrics)	25.85 kB	-	-
@sentry/browser (incl. Logs)	26.07 kB	-	-
@sentry/browser (incl. Metrics & Logs)	26.73 kB	-	-
@sentry/react	26.54 kB	-	-
@sentry/react (incl. Tracing)	43.79 kB	-	-
@sentry/vue	29.29 kB	-	-
@sentry/vue (incl. Tracing)	43.41 kB	-	-
@sentry/svelte	24.84 kB	-	-
CDN Bundle	27.25 kB	-	-
CDN Bundle (incl. Tracing)	42.24 kB	-	-
CDN Bundle (incl. Tracing, Replay)	78.96 kB	-	-
CDN Bundle (incl. Tracing, Replay, Feedback)	84.41 kB	-	-
CDN Bundle - uncompressed	80.06 kB	-	-
CDN Bundle (incl. Tracing) - uncompressed	125.49 kB	-	-
CDN Bundle (incl. Tracing, Replay) - uncompressed	242.03 kB	-	-
CDN Bundle (incl. Tracing, Replay, Feedback) - uncompressed	254.79 kB	-	-
@sentry/nextjs (client)	46.02 kB	-	-
@sentry/sveltekit (client)	41.97 kB	-	-
@sentry/node-core	51.61 kB	-	-
@sentry/node	161.54 kB	+0.02%	+22 B 🔺
@sentry/node - without tracing	93.05 kB	-	-
@sentry/aws-serverless	108.56 kB	-	-

View base workflow run

[github-actions]

node-overhead report 🧳

Note: This is a synthetic benchmark with a minimal express app and does not necessarily reflect the real-world performance impact in an application.

Scenario	Requests/s	% of Baseline	Prev. Requests/s	Change %
GET Baseline	8,774	-	10,990	-20%
GET With Sentry	1,755	20%	1,876	-6%
GET With Sentry (error only)	6,009	68%	7,515	-20%
POST Baseline	1,186	-	1,112	+7%
POST With Sentry	588	50%	515	+14%
POST With Sentry (error only)	1,031	87%	924	+12%
MYSQL Baseline	3,316	-	3,701	-10%
MYSQL With Sentry	475	14%	405	+17%
MYSQL With Sentry (error only)	2,657	80%	3,010	-12%

View base workflow run

[chargome]

LGTM!