v0.0.79

• Added context‑aware options (before, after, context) to the grep tool,
  with a helper to normalize integer arguments and an updated command template
  that includes -B, -A, and -C flags.
• Enhanced the patch‑file tool: now requires a non‑empty path, validates it
  against allowed paths, computes MD5 digests before and after patching to
  determine success, and returns a JSON payload with a success flag and
  message.
• Introduced a unified logging helper (OllamaChat::Logging#log) that lazily
  creates a logger, formats exceptions with backtraces, and supports an
  optional warn: flag to emit user‑visible warnings.
• Centralized logging across the application: chat, dialog, document cache,
  follow‑chat, history, and tag resolver now use the new log helper for all
  error, warning, and informational messages.
• Added an explicit versus implicit confirmation flow in the follow‑chat logic,
  logging the outcome of each tool call.
• Moved chat history storage from XDG CACHE to XDG STATE and added a new
  LOGFILE configuration entry in oc.rb.
• Updated the history module to use the new state‑based history path directly.
• Updated the default configuration to support the new grep options and
  adjusted the command template accordingly.
• Updated the spec helper to set temporary paths for history and log files
  during tests.
• Adjusted tests and specifications to reflect the new logging, history, and
  tool‑call behavior.