docs: 添加 CLAUDE.md 协作规范 + CI 集成测试

[NeverENG]

Summary

• 新增 CLAUDE.md：约定方案先行、外科手术式修改、原子性 commit、自动 PR/merge 规则
• CI 添加 integration job：编译 Server → 启动 → benchmark 验证

规则要点

1. 方案先行：先提多方案让用户选
2. 精准修改：不连带改动无关代码
3. 原子 commit：改完立刻提交
4. 自动 PR/merge：commit 后自动 PR，CI 通过自动 rebase merge

🤖 Generated with Claude Code

Summary by CodeRabbit

• New Features

  • Added session lifecycle notifications (session established/terminated messages).
  • Introduced block-indexed storage format for improved query performance.

• Bug Fixes

  • Improved error handling and validation across components.

• Improvements

  • Restructured logging system with standardized message prefixes.
  • Updated server name to "BanDB."
  • Enhanced CI pipeline to test feature branches.
  • Optimized persistence strategy for reduced write overhead.

• Documentation

  • Added comprehensive storage optimization design document.

[coderabbitai]

Caution

Review failed

The pull request is closed.

ℹ️ Recent review info

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Run ID: 21fa120c-b8e7-447e-b45c-1c4770736336

📥 Commits

Reviewing files that changed from the base of the PR and between 5c6d0c8 and 775d39e.

⛔ Files ignored due to path filters (9)

• Raft/raft_data/raft_log.dat is excluded by !**/*.dat
• Raft/raft_test_data_install_snap/raft_log.dat is excluded by !**/*.dat
• Raft/raft_test_data_log/raft_log.dat is excluded by !**/*.dat
• Raft/raft_test_data_snap_create/raft_log.dat is excluded by !**/*.dat
• Raft/raft_test_data_snap_persist/raft_log.dat is excluded by !**/*.dat
• Raft/raft_test_data_term/raft_log.dat is excluded by !**/*.dat
• Server/raft_data/raft_log.dat is excluded by !**/*.dat
• Server/raft_data/raft_state.dat is excluded by !**/*.dat
• Server/raft_data/snapshots/155040_2.snap is excluded by !**/*.snap

📒 Files selected for processing (20)

• .claude/settings.local.json
• .github/workflows/ci.yml
• CLAUDE.md
• Raft/raft.go
• Raft/raft_test.go
• Raft/raft_wal.go
• Raft/rpc.go
• Server/server.go
• Server/server_pprof.go
• config/config.json
• log/sstable_1777264896266900900.sst
• network/banNet/DataPack.go
• network/banNet/connection.go
• network/banNet/msgHandle.go
• network/banNet/server.go
• service/fsm.go
• service/router.go
• storage/zstorage/SSTable.go
• storage/zstorage/memtable.go
• 迭代方案/storage-bottleneck-optimization.md

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📝 Walkthrough

Walkthrough

This PR consolidates incremental Raft persistence refactoring, storage engine block-indexed SSTable format migration with MemTable WAL removal, connection lifecycle callback integration, and work-stealing message dispatch, alongside infrastructure updates and comprehensive optimization planning documentation.

Changes

Raft Persistence & Logging Refactor

Layer / File(s)	Summary
Raft incremental persistence and log append refactor Raft/raft.go, Raft/rpc.go, Raft/raft_wal.go	Introduces persistStateLocked() to persist only Term and votedFor; updates RequestVote, AppendEntries, and InstallSnapshot RPC paths to use incremental persistence instead of full persistLocked(); modifies AppendEntry to call wal.AppendLog() for individual entries; updates WAL SaveState to open/seek instead of truncate; adds RebuildLogFile() method.
Election fast path and snapshot handling with slog Raft/raft.go	Adds single-node election fast path (directly become leader when peer count is zero); migrates election startup, leader transition, snapshot auto-triggering, and snapshot replay to structured slog logging; maintains non-blocking ApplyCh behavior with logged skip on channel full.
Raft test infrastructure with per-test data directories Raft/raft_test.go	Updates all persistence and snapshot tests to use NewRaftWithDataDir with per-test dedicated directories, replacing prior shared "raft_data" cleanup; each test creates, removes before run, defers cleanup, and reloads via NewRaftWithDataDir to verify persisted state.

Storage Engine: Block-Indexed SSTable & MemTable WAL Removal

Layer / File(s)	Summary
SSTable block-indexed format and index cache storage/zstorage/SSTable.go	Introduces BlockIndexEntry type and SSTableBlockSize constant; adds indexCache and idxMu to SSTable struct; updates LoadSSTableMetaList to use slog, sort files, and asynchronously preheat block indices; replaces WriteToSSTable with block-based writer that builds per-block indices and writes footer.
SSTable read with block index and merge operations storage/zstorage/SSTable.go	Updates ReadAllFromSSTable to detect footer and stop at data end offset; implements new ReadFromSSTable using cached block index search with fallback to full scan; updates MergeSSTable to write merged output in block-indexed format and cache the merged index.
MemTable removes WAL persistence and updates logging storage/zstorage/memtable.go	Removes WAL write from Put and WAL tombstone write from Delete; updates WAL recovery, Flush, FlushToSSTable, and Compaction to use slog; removes debug prints from Get; maintains lookup order and persistence semantics.

Network & Service Integration: Connection Lifecycle & Message Dispatch

Layer / File(s)	Summary
Connection buffering and lifecycle logging network/banNet/connection.go, network/banNet/DataPack.go	Changes msgChan from unbuffered to buffered (capacity 10); removes msgChan write case from StartWriter fallback; updates logging strings to "commenced/closed/established/terminated" format with connection IDs; adds [ERROR] and [WARN] prefixes to DataPack logs.
Message handle work-stealing dispatch and logging network/banNet/msgHandle.go	Implements SendMsgToTaskQueue with worker ID derived from connection ID, priority enqueue to dedicated queue, bounded work-stealing, and blocking fallback; updates duplicate route and unregistered MsgID logging to [WARN]/[ERROR] format; updates worker startup and shutdown messaging.
Server lifecycle callbacks and connection management network/banNet/server.go, service/router.go, Server/server.go, Server/server_pprof.go	Adds OnConnStart and OnConnStop methods to Router that send session notifications via SendBuffMsg; updates Server start/stop logging messages; changes callback nil checks to [WARN] format; wires router callbacks to server via SetConnStartFunc/SetConnStopFunc.
Router message buffering and response paths service/router.go	Updates handlePut, handleGet, handleDelete to use SendBuffMsg instead of SendMsg for all responses; removes success-path log from handlePut.
FSM logging and Get error semantics service/fsm.go	Migrates KVServer.Run and KVServer.Apply to slog; changes Get to return "key not found" only when value is nil and err is nil, otherwise returning value/error without conversion; removes prior stdout snapshot messages.

Infrastructure, Configuration & Documentation

Layer / File(s)	Summary
CI workflow with integration test job .github/workflows/ci.yml	Extends on.push.branches to include feature/**; adds integration job that builds server/benchmark, starts server with GOMEMLIMIT=512MiB, polls port 8080 readiness, runs benchmark, and verifies final connectivity.
Configuration and Claude local settings config/config.json, .claude/settings.local.json	Updates server name to "BanDB"; adds Claude settings with permissions.allow for Go commands and Python -c pattern.
Comprehensive storage optimization design document 迭代方案/storage-bottleneck-optimization.md	Outlines storage bottlenecks and multi-phase optimization roadmap: P0 priorities (WAL batching, state persist merging, SSTable block indexing), P1-P3 enhancements (MANIFEST, connection pooling, snapshot caching), and architectural improvements (Leader lease reads, Multi-Raft partitioning, pipelined replication); includes Phase 1-7 timeline, file change summary, and risk assessment.

Estimated code review effort

🎯 4 (Complex) | ⏱️ ~75 minutes

Possibly related PRs

• NeverENG/BanDB#24: Refactors MemTable Put/Delete/Get behavior with active/dirty double-buffer, directly related to this PR's removal of WAL persistence and error semantics changes in the same methods.
• NeverENG/BanDB#33: Modifies Raft snapshot flow and InstallSnapshot handling, overlapping with this PR's snapshot replay and incremental persistence changes.

Poem

🐰 Hops through storage blocks with glee,
Raft logs persist incrementally,
Work-stealing queues and snapshots rebuild,
LSM teeth sharp, architecture skilled.
From chaos comes the roadmap clear—
Optimizations year by year!

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch feature/snapshot

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