chore: expand agent guidelines

[zxch3n]

Summary

• Expand root agent context with project structure, verified commands, workflow rules, and a short context index
• Add CLAUDE.md symlinks to AGENTS.md so Claude and Codex share the same context entries
• Add nested loro-internal agent indexes for encoding/import-export and state/mergeable-container work
• Add verified context articles for internal encoding and mergeable container concepts
• Add a self-maintained context policy and context discoverability backlog
• Add detailed WASM package agent guidance for pending event flushing, package outputs, and bundler validation
• Mine the most recent 100 commits and close the highest-priority context gaps found by cold-start subagent probes

Recent 100 Commit Mining

Theme	Signal	Context action
WASM packaging and bundler outputs	package metadata/changelog/build files were among the highest-churn files	Kept wasm package rules in crates/loro-wasm/AGENTS.md and fixed stale allowlist wording plus bundler smoke README expectation
Encoding/import/shallow snapshot behavior	repeated changes in fast_snapshot.rs, shallow_snapshot.rs, and import rollback tests	Indexed current modes, outdated modes, shallow/state-only/snapshot-at behavior, rollback, and validation shortcuts in context/internal-encoding.md
Mergeable containers	recent feature and follow-up fixes touch visibility, deterministic IDs, and tests	Indexed marker/cid model, conflict behavior, encoding retention, and test entrypoints in context/mergeable-containers.md
Pre-shallow history operations	subagent needed 10 hops to connect checkout/diff/revert safety to shallow root behavior	Added pre-shallow frontier safety to context/internal-encoding.md, pointing agents to SwitchToVersionBeforeShallowRoot and focused tests

Hop Measurement

Domain	Initial subagent result	Follow-up
Internal encoding	2 discovery hops: AGENTS.md -> context/internal-encoding.md	Healthy; no extra indexing needed
Mergeable containers	2 discovery hops: AGENTS.md -> context/mergeable-containers.md	Healthy; no extra indexing needed
WASM packaging	2 discovery hops: AGENTS.md -> crates/loro-wasm/AGENTS.md; found stale prototype wording and stale README expected JSON	Fixed both stale docs; post-fix verifier still found 2 hops and no inaccuracies
Shallow/import/undo seam	10 hops for pre-shallow checkout/diff/revert constraints	Added missing index entry; post-fix verifier found 2 hops and no inaccuracies

Validation

• Reinstalled and reread zxch3n/context-engineering skill
• wc -m budget check for AGENTS files
• Markdown relative-link resolver script
• git diff --check origin/main...HEAD
• Scanned updated context files for TODO/placeholder text
• Cross-checked new claims against crates/loro-wasm/index.ts, examples/bundler-smoke-tests/scripts/run.mjs, crates/loro-internal/src/loro.rs, and shallow-root regression tests
• Ran two post-fix cold-start verifier subagents for WASM pending-event wrappers and pre-shallow checkout/diff/revert indexing

Docs/context-only change; no Rust or JS tests were run.

[github-actions]

WASM Size Report

• Original size: 3031.66 KB
• Gzipped size: 1000.27 KB
• Brotli size: 702.63 KB