Upgraded the CLI

[memuguenstig-lab]

Summary

This PR turns the Pointer CLI into a much more scriptable and discoverable tool by adding proper top-level management commands, config validation, doctor output for automation, and better shell completion.

What changed

CLI management

• added pointer init --non-interactive for prompt-free setup
• added pointer config show
• added pointer config set
• added pointer status as a real top-level command

Diagnostics

• added pointer doctor
• added pointer doctor --json for machine-readable output
• added explicit CLI exit codes for config errors, dependency/doctor failures, and user-cancelled init

Context management

• added top-level pointer context commands:
  • show
  • refresh
  • search
  • config
  • enable
  • disable

Config improvements

• added dotted-key config access and updates
• added config validation for common invalid states like bad API URLs, empty model names, or invalid numeric values
• validation now stops commands early with clearer errors

Autocompletion

• re-enabled Typer shell completion
• added smarter completion for config keys
• added value suggestions for pointer config set
• added context-based suggestions for pointer context search

Tests and docs

• added CLI tests for:
  • config commands
  • doctor output
  • status
  • context commands
  • completion helpers
• updated CLI README with the new commands and completion setup

Why

Before this change, the CLI was mostly centered around the interactive chat flow. This PR makes it much easier to:

• automate setup
• inspect and modify configuration safely
• debug local environments
• use codebase context outside the chat loop
• navigate commands faster via shell completion

Verification

• verified Python syntax with py_compile
• added unit tests for the new config, doctor, main-command, and completion paths

Notes

pytest could not be executed in the current environment because the available Python interpreter did not have pytest installed.