[Feature]: Document view of a specification  #69

What type of issue is this?

• Bug report
• Feature request

Prerequisites

• I have written a descriptive issue title
• I have verified that I am running the latest version of the reqifviewer
• I have searched open and closed issues to ensure it has not already been reported

Description

Today a specification is a tree of labels next to a panel that starts with "Long Name: NOT SET" and an attribute grid, with the requirement text in a truncated grid cell. Reviewers want to read the specification as a document.

Acceptance criteria

• A specification reads like a document: chapter headings with numbers derived from the hierarchy, each requirement as a block with its id badge, its text (XHTML with images inline, see [Feature]: Show pictures inline in rich text  #71) and a few key attributes as chips (for example status).
• An outline (chapters only) in a resizable side panel, synced with scrolling; selecting a chapter scrolls to it.
• Clicking a requirement opens [Feature]: Requirement details panel  #70.
• Virtualized rendering, so a specification with thousands of objects stays fast ([Feature]: Large files: virtualization and progress  #78).

Steps to Reproduce

Load requirements-and-objects.reqifz or ProR_Traceability-Template-v1.0.reqif (reqifviewer.Tests/TestData) and look at the pages mentioned above.

System Configuration

• reqifviewer version: 6.1.0 (development, with [Refactor] Blazor Blueprint app shell and Blazor Web App hosting #56)
• Environment (Operating system, version and so on): Windows 11, Chrome
• .NET Framework version: .NET 10
• Additional information: Plan item R-03 of the viewer improvement plan. Size: L. Depends on: [Bug]: Sanitize XHTML from ReqIF files before rendering it  #57, [Feature]: Readable labels for requirements: detect the id and text attributes  #68.