[wadrzl]

Closes #110

Implements mem put <dir> --watch for automatic one-way ingestion of new/changed files from a watched directory into mem.

What changed

CLI flag

• Added --watch / -w flag to mem put command
• Requires a directory path (errors on files or stdin)
• Polls every 5s (interval hardcoded, could be configurable in future)

Watch daemon (watchDir)

• Polling loop with size-based change detection
• Tracks file states (path → last known size) in memory
• Ingests new/changed files via existing uploadFile path
• Skips hidden files/directories (starting with .)
• Computes relative paths for target folder structure

Per-cycle reports

• Text format: Cycle N: scanned=X ingested=Y unchanged=Z failed=W
• JSON format (--format json): machine-readable report object
• Failures listed per file with error messages
• Daemon continues on individual file failures (fail-closed per file)

Graceful lifecycle

• SIGINT/SIGTERM handling for clean shutdown
• Exits cleanly if watched directory disappears
• No write-back to local disk (strictly one-way)
• No deletion propagation (local deletes don't remove mem content)

Requirements covered

• REQ-001: One-way watch daemon — mem put <path> --watch watches directory and ingests new/changed files
• REQ-002: Per-cycle import report — each cycle emits report with added/unchanged/failed counts
• REQ-003: Boundary hard constraints — no write-back, no deletion propagation, no bidirectional sync
• REQ-004: Canon consolidation — formal tracking item for scan/auto-sync family

Non-goals (by design)

• No bidirectional sync, conflict resolution, or deletion propagation (Phase 2)
• No fsnotify/event-driven watching (polling is simpler and portable)
• No mobile/share-link/preview scope creep
• No re-indexing behavior changes beyond what ingestion already triggers

Test plan

• Manual: mem put ./test-dir --watch, add files, verify ingestion
• Manual: Modify file, verify re-ingestion
• Manual: Delete local file, verify mem content NOT deleted
• Manual: Ctrl+C, verify clean shutdown
• CI green
• Reviewer approval from @waterbro-8

[waterbro-8]

REQUEST_CHANGES。请关掉本 PR，不要 Closes #110。

• #110 已有实现： mem #225（sun-970，head bf68d03d，已 APPROVE，含 cmds_watch*.go、跨平台 lock、测试、ingest）。本 PR 是同一 issue 的第二份、更薄的 fork 实现。
• 本切片缺测试、CI 未跑；变更检测只用 size，同大小改内容会漏；printWatchReportJSON 手拼 JSON；signal.Notify(..., os.Kill) 接不住 SIGKILL 也不是可移植的优雅退出。
• 我推不了 fork。请 close #226，让 #225 rebase 到最新 main 后合。作者 wadrzl 未映射钉钉。

[wadrzl]

Closing — duplicates already APPROVED #225.