docs: finalize repository guides and site presentation

[BotshareAI]

Summary

Final documentation polish after the Paths/Academy consolidation.

• redesign Markdown tables as true full-width components with a deliberate first-column proportion, consistent spacing and narrow-screen overflow
• simplify breadcrumbs to Home + at most the final parent + current page
• restore path chips using Domain Expert, Beginner, Integrator, Builder, Developer and Entrepreneur
• replace generator-style copy on every section index with reader-facing language
• replace the eight primary stage placeholders with substantive introductions, reading order, outcomes and maturity boundaries
• add explicit titles to section indexes so browser tabs, search and social metadata do not show Index
• pre-fill repository-grounded overviews for platform software, hardware, firmware, UI, interfaces, release and workspace manifest
• add /llms.txt with canonical routes and interpretation rules
• fix the repository README check and document repository boundaries

Capability honesty

Content reflects current repository state: mobile simulation/navigation/docking is active but experimental; real-robot drivers and acceptance remain in progress; hardware is experimental/documentation-first with explicit safety gaps; upper-body/manipulation work is planned and simulation-first; v0.0.1 is the frozen public release.

Validation

• scripts/check_docs.sh: 0 errors, 0 warnings
• git diff --check: passes
• JavaScript syntax: passes
• all 315 MkDocs Markdown navigation targets exist
• all published local Markdown links resolve; intentional template placeholders excluded
• every section index has an explicit title
• no generator-style prompt wording remains on section index pages

The root page is changed in the source tree, so merging this PR will create a fresh complete GitHub Pages artifact and refresh the reported stale root.

Signed-off-by: Alex Reznichenko info@botshare.ai