Add adaptive guided tours to the new UI

[niemyjski]

Context

Replacement for #2458, which was merged prematurely and reverted by #2505. This PR restores the exact reviewed feature tree from commit 9be6a7660a6b966573dece7d669dd822c4d34c92 for continued review. It must not be merged until explicitly approved by Blake.

What changed

• adds a client-only, lazily loaded guided-tour system for the Svelte UI using Driver.js
• shows a server-synchronized welcome chooser once while keeping skipped guides replayable
• adds Guided Tours to command search and Help, with responsive catalog and availability states
• resumes navigation-spanning guides from stable step IDs and coordinates dialogs, sheets, navigation, logout, organization changes, reduced motion, and focus restoration
• adds Explore the new UI, Configure a project, Create a saved view, Investigate an error, and Meet Exie guides
• records privacy-safe usage telemetry using stable guide/version/step/source/outcome identifiers

API and persistence

• adds product_tours to persisted and current-user models; legacy records default to an empty map
• adds self-only PUT /api/v2/users/me/product-tours/{tourId} with bounded IDs, positive versions, known statuses, a 32-entry cap, server timestamps, idempotent merging, stale-version protection, and completed precedence
• updates HTTP examples, endpoint/OpenAPI snapshots, serialization coverage, and generated frontend models

Safety and compatibility

• Svelte UI only; legacy Angular remains unchanged
• no automatic destructive project, saved-view, stack, tab, Exie prompt, or provider action
• existing public API behavior remains backwards compatible
• restored tree is byte-for-byte identical to the final head of Add adaptive guided tours to the new UI #2458

Verification inherited from the restored exact head

• npm run validate and npm run build passed
• 79 frontend test files / 629 tests passed
• 2,866 backend tests passed with 3 intentional skips
• focused API 53/53 and OpenAPI 4/4 passed
• hosted 36-scenario Playwright E2E suite, API, client, Docker build, version, and CLA passed
• desktop/mobile dogfood covered catalog, overview, persisted restart, safe navigation, and teardown

Breaking changes

None.

[github-actions]

Package	Line Rate	Branch Rate	Complexity	Health
Exceptionless.Insulation	37%	35%	286	❌
Exceptionless.Core	75%	67%	10184	✔
Exceptionless.Web	85%	69%	7933	✔
Exceptionless.AppHost	38%	41%	147	❌
Summary	78% (25228 / 32216)	67% (11842 / 17582)	18550	✔