docs: enrich README and introduction with architecture overview from DeepWiki

[monsieurbulb]

What this does

Updates README.md and docs/introduction.md with richer architecture documentation sourced from DeepWiki.

README.md changes

• Added Architecture section describing the dual-track spec + Rust node design
• Expanded Repository Structure table to include javm/ and tools/ directories
• Added Key Components section covering Grey, JAVM, and Formal Specification
• Added Data Flow pipeline (Join → Accumulate → Refine)
• Expanded Quick Start with prerequisites and local testnet modes
• Added Further Reading section linking to DeepWiki

docs/introduction.md changes

• Added Core Concepts with timeslot/epoch/core table
• Added Join-Accumulate-Refine Pipeline breakdown
• Added State and Services with Greek letter notation table
• Added Coinless Design explanation
• Added Consensus and Finality (Safrole + Data Availability)
• Added Key Differences from Gray Paper section
• Added Further Reading links

No code changes — documentation only.

[github-actions]

Genesis Review

Comparison targets:

• 97d8b6b0 (97d8b6b)
• 6b4d0f45 (6b4d0f4)
• 1045647e (1045647)
• e23cfed2 (e23cfed)
• bf816b61 (bf816b6)
• 91878cf0 (91878cf)
• a35553d4 (a35553d)

How to review

Post a comment with the following format (rank from best to worst):

/review
difficulty: <commit1>, <commit2>, ..., <commitN>, currentPR
novelty: <commit1>, <commit2>, ..., <commitN>, currentPR
design: <commit1>, <commit2>, ..., <commitN>, currentPR
verdict: merge

Use the short commit hashes above and currentPR for this PR.
Each line ranks all comparison targets + this PR from best to worst.

To meta-review another reviewer's comment, react with 👍 or 👎.

[johandroid]

/review
difficulty: 97d8b6b, 1045647, 91878cf, bf816b6, e23cfed, currentPR, 6b4d0f4, a35553d
novelty: e23cfed, 97d8b6b, 1045647, bf816b6, 91878cf, currentPR, 6b4d0f4, a35553d
design: 97d8b6b, 1045647, 91878cf, e23cfed, bf816b6, currentPR, 6b4d0f4, a35553d
verdict: merge

Expands the top-level README and introduction into a clearer architectural entry point, with useful links and current component framing. This is valuable project-facing documentation, but it ranks below the Genesis/scoring, dependency-security, runtime debug, test, and store-refactor targets because it is mostly explanatory rather than structural. Merge is reasonable for docs-only onboarding improvement.

[github-actions]

JAR Bot: Review recorded from @johandroid (1 reviews, 0 meta-reviews).
Merge weight: 0/37665 (need >50%).