♻️ Rewrite SessionManager with reactive strategy interface

[thomas-lebeau]

Motivation

The existing SessionManager and SessionStore architecture has accumulated complexity through layered abstractions (sessionStore.ts, sessionStoreOperations.ts, product-specific wrappers). This makes it difficult to adopt modern browser APIs like the CookieStore API and Web Locks, and the synchronous mutex-based approach creates contention issues.

This PR rewrites the session management layer with a reactive strategy interface, preparing the foundation for async-first storage (CookieStore API) in v7.

Changes

• Redefine SessionStoreStrategy interface — strategies now own their state and expose it reactively via an observable, replacing the synchronous read/write/mutex pattern
• Rewrite all three storage strategies (cookie, localStorage, memory) to implement the new reactive interface
• Cookie strategy uses Web Locks for cross-tab coordination and cookieObservable for change detection, replacing the polling-based mutex
• Introduce CookieAccess abstraction to decouple cookie read/write from the document.cookie API, preparing for CookieStore API adoption
• Merge SessionStore into SessionManager — remove sessionStore.ts and sessionStoreOperations.ts, consolidating session lifecycle logic into a single module
• Make SessionManager initialization fully async — startSessionManager now returns Promise<SessionManager>, with setSessionState also async across all strategies
• Remove product-specific session manager wrappers (rumSessionManager.ts, logsSessionManager.ts) — the generic SessionManager now handles all products
• Remove TrackingType generic parameter from SessionManager — session tracking decisions are no longer encoded in the session manager type

Test instructions

yarn test:unit --spec packages/core/src/domain/session/sessionManager.spec.ts
yarn test:unit --spec packages/core/src/domain/session/storeStrategies/sessionInCookie.spec.ts
yarn test:unit --spec packages/core/src/domain/session/storeStrategies/sessionInLocalStorage.spec.ts
yarn test:unit --spec packages/core/src/domain/session/storeStrategies/sessionInMemory.spec.ts

Checklist

• Tested locally
• Tested on staging
• Added unit tests for this change.
• Added e2e/integration tests for this change.
• Updated documentation and/or relevant AGENTS.md file

[cit-pr-commenter-54b7da]

Bundles Sizes Evolution

📦 Bundle Name	Base Size	Local Size	𝚫	𝚫%	Status
Rum	170.83 KiB	169.31 KiB	-1.52 KiB	-0.89%	✅
Rum Profiler	6.18 KiB	6.18 KiB	0 B	0.00%	✅
Rum Recorder	27.48 KiB	27.70 KiB	+227 B	+0.81%	✅
Logs	56.45 KiB	54.53 KiB	-1.91 KiB	-3.39%	✅
Rum Slim	128.07 KiB	126.68 KiB	-1.39 KiB	-1.09%	✅
Worker	23.63 KiB	23.63 KiB	0 B	0.00%	✅

🚀 CPU Performance

Pending...

🧠 Memory Performance

Pending...

🔗 RealWorld

[datadog-prod-us1-4]

⚠️ Tests

✨ Fix all issues with BitsAI or with Cursor

⚠️ Warnings

🧪 10 Tests failed

startSessionManager initialization should fire onReady after initialization from Chrome 63.0.3239.84 (Windows 10) (Datadog) (Fix with Cursor)

Error: Expected spy onReady to have been called once. It was called 0 times.
    at <Jasmine>
    at UserContext.it (webpack:///packages/core/src/domain/session/sessionManager.spec.ts:149:26 <- /tmp/_karma_webpack_568744/commons.js:43707:32)
    at <anonymous>

microfrontend › Logs › expose handling stack for console.log from microfrontend.scenario.ts (Datadog) (Fix with Cursor)

microfrontend.scenario.ts:422:15 expose handling stack for console.log

[Firefox] › microfrontend.scenario.ts:422:15 › microfrontend › Logs › expose handling stack for console.log 

    Error: expect(received).toEqual(expected) // deep equality

    - Expected  - 1
    + Received  + 6

      Object {
...

microfrontend › Logs › expose handling stack for DD_LOGS.logger.log from microfrontend.scenario.ts (Datadog) (Fix with Cursor)

microfrontend.scenario.ts:444:15 expose handling stack for DD_LOGS.logger.log

[Firefox] › microfrontend.scenario.ts:444:15 › microfrontend › Logs › expose handling stack for DD_LOGS.logger.log 

    Error: expect(received).toEqual(expected) // deep equality

    - Expected  - 1
    + Received  + 6

      Object {
...

View all

ℹ️ Info

No other issues found (see more)

❄️ No new flaky tests detected

🎯 Code Coverage (details)
• Patch Coverage: 83.12%
• Overall Coverage: 77.62% (+0.33%)

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