feat(cli): Improve help text, error handling, and add fuzzy command suggestions

CLI help improvements (cli/mod.rs):
- Add descriptive help text to all global flags (-c, --robot, -J, etc.)
- Add descriptions to all subcommands (Issues, Mrs, Sync, etc.)
- Add --no-quiet flag for explicit quiet override
- Shell completions now shows installation instructions for each shell
- Optional subcommand: running bare 'lore' shows help in terminal mode,
  robot-docs in robot mode

Structured clap error handling (main.rs):
- Early robot mode detection before parsing (env + args)
- JSON error output for parse failures in robot mode
- Semantic error codes: UNKNOWN_COMMAND, UNKNOWN_FLAG, MISSING_REQUIRED,
  INVALID_VALUE, ARGUMENT_CONFLICT, etc.
- Fuzzy command suggestion using Jaro-Winkler similarity (>0.7 threshold)
- Help/version requests handled normally (exit 0, not error)

Robot-docs enhancements (main.rs):
- Document deprecated command aliases (list issues -> issues, etc.)
- Document clap error codes for programmatic error handling
- Include completions command in manifest
- Update flag documentation to show short forms (-n, -s, -p, etc.)

Dependencies:
- Add strsim 0.11 for Jaro-Winkler fuzzy matching

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Cargo.toml

@@ -47,6 +47,7 @@ flate2 = "1"
 chrono = { version = "0.4", features = ["serde"] }
 uuid = { version = "1", features = ["v4"] }
 regex = "1"
+strsim = "0.11"
 
 [target.'cfg(unix)'.dependencies]
 libc = "0.2"