chore(claude): move claude.md into .claude and split rules into individual files

[m-kus]

TL;DR

Reorganize Claude's guidance files into a more structured format with dedicated rules and improved code style guidelines.

What changed?

• Moved main Claude instructions from root CLAUDE.md to .claude/CLAUDE.md
• Reorganized code guidelines from a single file into multiple specialized rule files:
  • Created dedicated rule files for debugging, verification, code review, testing, etc.
  • Expanded code style guidelines with more detailed sections on naming, edge cases, and module organization
  • Added security considerations from recent audit findings to discovery service specs
• Added new rules for auto-updating guidelines based on code review feedback
• Updated error handling documentation in discovery service specs

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This change is 

[m-kus]

• feat(discovery-core): add transfer preflight check #474
• feat(discovery-core): add outgoing state sync orchestrator #473
• feat(discovery-core): add incoming state sync orchestrator #472
• feat(discovery-core): add paginated last-note-index search with bisection #471
• feat(discovery-core): add paginated outgoing channel discovery #470
• feat(discovery-core): paginated notes discovery with nullifier filtering #462
• feat(discovery-core): paginated subchannel discovery with cursor support #461
• feat(discovery-core): paginated incoming channel discovery with cursor support #460
• feat(discovery-core): add iobudget batching, cursor types, and new cost constants #459
• feat(discovery-core): add secretfelt type and unify key param naming #458
• feat(discovery-core): add batch iviews methods and outgoing channel support #457
• feat(discovery-core): add hash primitives and outgoing channel storage slots #456
• chore(claude): move claude.md into .claude and split rules into individual files #455 👈 (View in Graphite)
• refactor(indexer): move devnet dump generation to a separate script, scaffold e2e tests dir #454
• fix(sdk): sync sdk with cairo contract renames (to_addr, enc_user_addr_hash) #469
• main

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[Yoni-Starkware]

@Yoni-Starkware partially reviewed 10 files and all commit messages, and made 1 comment.
Reviewable status: complete! all files reviewed, all discussions resolved (waiting on @m-kus).