docs: rebuild the guides and normalize the RFC corpus

[aaltshuler]

Summary

• Rebuild the user guide as 24 short, task-focused pages that explain the product without implementation archaeology.
• Replace stale plans, handoffs, snapshots, and copied designs with 17 current developer guides.
• Normalize all 35 formal decisions under docs/rfcs/ with four-digit filenames, uniform frontmatter, separate decision and implementation states, and one registry.
• Use a Source → Supports → Claim evidence graph in the quickstart so the first example has two node types and one edge type.
• Add scripts/check-docs.py to enforce links, anchors, audience boundaries, RFC placement, metadata, and registry consistency.
• Repair documentation references in source comments so every referenced local document exists.

Scope

This is one clean commit on current main after #545 and #549 landed.

• No Cargo, graph-vocabulary guard, vocabulary inventory, OpenAPI, Azure runtime, deployment, or package changes.
• Rust changes are documentation comments and links only; runtime behavior is unchanged.
• The workflow change only invokes the new documentation checker.
• User documentation remains outside the exact-occurrence graph-vocabulary gate added by ci: exclude user docs from vocabulary guard #549. OpenAPI, Rust presentation strings, and public Rust remain guarded.

Validation

• python3 scripts/check-docs.py — 109 Markdown files
• bash scripts/check-agents-md.sh — 45 links / 43 docs
• python3 scripts/check-workflow-action-pins.py — 50 external uses, all pinned
• actionlint .github/workflows/*.yml
• cargo fmt --all --check
• cargo test -p omnigraph-vocabulary-guard --locked — 51 passed
• Exact-main OpenAPI vocabulary check — 15 current / 15 base
• Exact-main Rust-string vocabulary check — 834 current / 834 base
• git diff --check origin/main
• Exact diff guard confirms Cargo.toml, Cargo.lock, and tools/omnigraph-vocabulary-guard are unchanged
• Source-comment documentation-link scan — no missing targets

The full workspace suite was not run because this change does not alter runtime behavior.

Greptile Summary

Rebuilds the user and developer guides, normalizes the RFC corpus and registry, and adds CI validation for documentation structure.

• Reorganizes user documentation into task-focused guides.
• Consolidates current developer guidance and repairs source-comment documentation references.
• Standardizes RFC filenames, metadata, lifecycle states, and registry entries.
• Adds scripts/check-docs.py to validate links, anchors, audience boundaries, and RFC consistency.

Confidence Score: 5/5

The PR appears safe to merge.

The previously reported incomplete Expand tuning reference is now accurate and complete, and no blocking failure remains.

Important Files Changed

Filename	Overview
scripts/check-docs.py	Adds documentation and RFC consistency validation used by CI.
.github/workflows/ci.yml	Runs the new documentation checker in the existing CI documentation checks.
docs/dev/execution.md	Accurately documents both Expand dispatch caps, defaults, override parsing, and automatic path selection.
crates/omnigraph/src/exec/query.rs	Updates the Expand tuning comment to reference the complete execution guide.
docs/rfcs/README.md	Establishes the normalized RFC registry and separates decision status from implementation status.
AGENTS.md	Replaces encyclopedic content with a concise repository and documentation map.

_{Reviews (6): Last reviewed commit: "docs: rebuild guides and normalize RFC c..." | Re-trigger Greptile}