docs: Remove outdated development plan document

PLAN.md

@@ -1,113 +0,0 @@
-# Development Plan for Keep
-
-## Overview
-Keep is a command-line tool for managing temporary files with automatic compression, metadata generation, and querying capabilities. It includes a REST API server and supports extensible plugins for compression, metadata, and filtering.
-
-## Current Status (as of latest updates)
-The project is in a functional state with core features implemented. Key components:
-
-### Core Features
-- **Save Mode**: Stores content with compression and metadata generation. Supports tags and custom metadata via environment variables.
-- **Get Mode**: Retrieves item content by ID or tags, with optional filtering (head, tail, grep, etc.) and binary detection.
-- **List Mode**: Lists items with customizable table format, sorting, and filtering by tags/metadata.
-- **Delete Mode**: Deletes items by ID.
-- **Info Mode**: Shows detailed information about an item including metadata.
-- **Diff Mode**: Compares two items using the `diff` utility.
-- **Status Mode**: Displays system status including paths, compression engines, and configured plugins.
-- **Status Plugins Mode**: Shows detailed plugin configurations and available options.
-
-### Compression Engines
-- Built-in: LZ4, GZip, None.
-- External programs: BZip2, XZ, ZStd (via `CompressionEngineProgram`).
-- Factory system for selecting engines with fallback to default (LZ4 if available).
-
-### Meta Plugins
-- **Text**: Detects binary/text content, counts lines/words, tracks line length statistics (max, mean, median).
-- **Cwd**: Captures current working directory.
-- **User**: Captures user ID, group ID, username, group name.
-- **Shell**: Captures shell environment.
-- **ShellPid/KeepPid**: Captures parent and current process IDs.
-- **Digest**: Computes MD5, SHA256, SHA512 hashes (configurable).
-- **MagicFile**: Detects MIME type, encoding, and file type using libmagic.
-- **Hostname**: Captures short/full hostname with DNS resolution.
-- **Exec**: Runs external programs for custom metadata.
-- **Env**: Captures environment variables prefixed with `KEEP_META_`.
-- Plugin registry and configuration via YAML (options/outputs mapping).
-
-### Filter Plugins
-- **Head/Tail/Skip**: Bytes and lines (head_bytes(10), tail_lines(5), etc.).
-- **Grep**: Regex pattern matching on lines.
-- **StripAnsi**: Removes ANSI escape sequences.
-- Chainable via filter strings (e.g., "head_lines(10)|grep(pattern=error)").
-
-### Server Mode
-- REST API with endpoints: `/api/status`, `/api/item/` (list/post), `/api/item/{id}/meta`, `/api/item/{id}/content`, `/api/item/latest/*`.
-- Authentication: Bearer token or Basic auth (password or hashed).
-- MCP (Model Context Protocol) support via SSE and JSON-RPC tools (save_item, get_item, list_items, etc.).
-- OpenAPI/Swagger documentation.
-- HTML pages for item listing and details.
-- Streaming support for large content with offset/length parameters.
-- Binary content detection and restriction.
-
-### Configuration
-- YAML config file (`~/.config/keep/config.yml`) with overrides from env vars and CLI.
-- Table customization: columns, alignment, colors, styles (ASCII/UTF8).
-- Plugin configuration: enable/disable outputs, custom options.
-
-### Database
-- SQLite with schema for items, tags, metadata.
-- Migrations for schema evolution.
-- Indexes on tags and metadata names.
-- Foreign key constraints.
-
-### Testing
-- Unit tests for compression engines, meta plugins, filter plugins, database operations.
-- Integration tests for modes (save, get, list, etc.).
-- Test helpers for temp files/DBs.
-
-### Other
-- Binary detection using signatures and printable character ratio.
-- Human-readable size formatting.
-- Logging with configurable verbosity.
-- Error handling with structured errors (`CoreError`).
-
-## Completed Changes
-- Implemented full plugin system for meta and filters with registry via ctors.
-- Added async item service for server mode with blocking task spawning.
-- Enhanced server API with streaming, pagination, and MCP integration.
-- Improved configuration with table styling and plugin output mapping.
-- Added binary detection in get mode and API.
-- Implemented diff mode with pipes and compression handling.
-- Created status and status-plugins modes with detailed output.
-- Added generate-config mode with commented defaults.
-- Integrated libmagic for file type detection.
-- Enhanced text meta plugin with line/word statistics.
-- Added exec meta plugin for external commands.
-- Implemented filter parsing with pest grammar.
-- Added HTML UI for server with item listing and details.
-
-## Remaining/Planned Tasks
-- **Documentation**: Update README.md with installation, usage examples, API docs.
-- **More Plugins**: Add file size, creation time plugins if needed.
-- **Performance**: Optimize streaming for very large files; add content caching.
-- **Security**: Add rate limiting to API; validate input more strictly.
-- **Features**:
-  - Update mode for modifying existing items.
-  - Search mode with full-text search on metadata/content.
-  - Export/import database.
-  - Backup/restore functionality.
-- **Testing**: Add more integration tests for server API and MCP.
-- **Polish**:
-  - Improve error messages and user feedback.
-  - Add progress indicators for large operations.
-  - Support for custom compression plugins.
-- **Packaging**: Create installation scripts, Docker support.
-
-## Potential Improvements
-- Switch to a more efficient database for large datasets (e.g., SQLite with WAL mode).
-- Add WebSocket support for real-time updates in server mode.
-- Implement plugin hot-reloading for development.
-- Add CLI completion (bash/zsh/fish).
-- Support for archiving old items automatically.
-
-Last updated: After codebase initialization and feature implementation.