✨ add UNSTABLE_useVueComponentTracker composable

[mormubis]

Motivation

Fourth of five PRs (#4325, #4327, #4328 are the first three). Adds component-level performance tracking.

Changes

`UNSTABLE_useVueComponentTracker('MyComponent')` called inside `setup()` measures how long a component takes to mount and update using Vue's lifecycle hooks, reporting `vueComponentRender` duration vitals with `{ is_first_render: boolean, framework: 'vue' }`. Same vital name as `rum-react`'s `reactComponentRender` so cross-framework dashboards just work. Marked `UNSTABLE_` to match the React counterpart.

Test instructions

```bash
yarn test:unit --spec packages/rum-vue/src/domain/performance/useVueComponentTracker.spec.ts
```

Checklist

• Tested locally
• Tested on staging
• Added unit tests for this change
• Added e2e/integration tests
• Updated documentation (will come once the API is settled)

[datadog-prod-us1-6]

⚠️ Tests

✨ Fix all issues with BitsAI or with Cursor

⚠️ Warnings

🧪 2 Tests failed

UNSTABLE_useVueComponentTracker reports a vueComponentRender vital on mount from Chrome 63.0.3239.84 (Windows 10) (Datadog) (Fix with Cursor)

TypeError: Object.fromEntries is not a function
    at getComponentsFromStubs (webpack:///node_modules/@vue/test-utils/dist/vue-test-utils.esm-bundler.mjs:290:1 <- /tmp/_karma_webpack_500976/commons.js:140285:19)
    at createInstance (webpack:///node_modules/@vue/test-utils/dist/vue-test-utils.esm-bundler.mjs:8305:1 <- /tmp/_karma_webpack_500976/commons.js:148300:24)
    at mount (webpack:///node_modules/@vue/test-utils/dist/vue-test-utils.esm-bundler.mjs:8365:1 <- /tmp/_karma_webpack_500976/commons.js:148360:14)
    at UserContext.it (webpack:///packages/rum-vue/src/domain/performance/useVueComponentTracker.spec.ts:27:16 <- /tmp/_karma_webpack_500976/commons.js:113282:69)
    at <Jasmine>

UNSTABLE_useVueComponentTracker reports is_first_render: false on update from Chrome 63.0.3239.84 (Windows 10) (Datadog) (Fix with Cursor)

TypeError: Object.fromEntries is not a function
    at getComponentsFromStubs (webpack:///node_modules/@vue/test-utils/dist/vue-test-utils.esm-bundler.mjs:290:1 <- /tmp/_karma_webpack_500976/commons.js:140285:19)
    at createInstance (webpack:///node_modules/@vue/test-utils/dist/vue-test-utils.esm-bundler.mjs:8305:1 <- /tmp/_karma_webpack_500976/commons.js:148300:24)
    at mount (webpack:///node_modules/@vue/test-utils/dist/vue-test-utils.esm-bundler.mjs:8365:1 <- /tmp/_karma_webpack_500976/commons.js:148360:14)
    at UserContext.it (webpack:///packages/rum-vue/src/domain/performance/useVueComponentTracker.spec.ts:58:32 <- /tmp/_karma_webpack_500976/commons.js:113309:85)
    at <Jasmine>

ℹ️ Info

No other issues found (see more)

❄️ No new flaky tests detected

🎯 Code Coverage (details)
• Patch Coverage: 88.24%
• Overall Coverage: 77.30% (+0.01%)

_{This comment will be updated automatically if new data arrives.
🔗 Commit SHA: db60fb6 | Docs | Datadog PR Page | Was this helpful? React with 👍/👎 or give us feedback!}

[cit-pr-commenter-54b7da]

Bundles Sizes Evolution

📦 Bundle Name	Base Size	Local Size	𝚫	𝚫%	Status
Rum	175.02 KiB	175.02 KiB	0 B	0.00%	✅
Rum Profiler	6.16 KiB	6.16 KiB	0 B	0.00%	✅
Rum Recorder	27.46 KiB	27.46 KiB	0 B	0.00%	✅
Logs	56.80 KiB	56.80 KiB	0 B	0.00%	✅
Rum Slim	130.66 KiB	130.66 KiB	0 B	0.00%	✅
Worker	23.63 KiB	23.63 KiB	0 B	0.00%	✅

🚀 CPU Performance

Action Name	Base CPU Time (ms)	Local CPU Time (ms)	𝚫%
RUM - add global context	0.0041	0.0042	+2.44%
RUM - add action	0.0153	0.0138	-9.80%
RUM - add error	0.0129	0.0136	+5.43%
RUM - add timing	0.0028	0.0029	+3.57%
RUM - start view	0.0121	0.0128	+5.79%
RUM - start/stop session replay recording	0.0007	0.0008	+14.29%
Logs - log message	0.016	0.0169	+5.62%

🧠 Memory Performance

Action Name	Base Memory Consumption	Local Memory Consumption	𝚫
RUM - add global context	26.02 KiB	26.71 KiB	+705 B
RUM - add action	51.99 KiB	51.49 KiB	-513 B
RUM - add timing	26.92 KiB	26.85 KiB	-72 B
RUM - add error	55.48 KiB	54.98 KiB	-515 B
RUM - start/stop session replay recording	26.04 KiB	26.03 KiB	-13 B
RUM - start view	466.71 KiB	465.58 KiB	-1.13 KiB
Logs - log message	43.94 KiB	44.51 KiB	+577 B

🔗 RealWorld