feat(zsh-vi-man): add plugin for smart man page lookup

Adds zsh-vi-man plugin that provides smart man page lookup for zsh vi mode
and emacs mode. Press K in vi normal mode, Ctrl-X k in emacs mode, or Ctrl-K
in vi insert mode on any command or option to open its man page.

Features:
- Smart subcommand detection (git commit → man git-commit)
- Option jumping (grep -r → jumps to -r entry in man page)
- Combined options support (rm -rf → finds both -r and -f)
- Pipe support (cat file | grep -i → opens man grep)
- Multiple pager support (less, vim, nvim)

plugins/zsh-vi-man/lib/parser.zsh

@@ -0,0 +1,49 @@
+# lib/parser.zsh - Word and command parsing utilities
+# Extracts words and commands from the command line buffer
+
+# Get the word at the current cursor position
+# Uses LBUFFER and RBUFFER which are ZLE special variables
+zvm_parse_word_at_cursor() {
+  local left="${LBUFFER##*[[:space:]]}"
+  local right="${RBUFFER%%[[:space:]]*}"
+  echo "${left}${right}"
+}
+
+# Get the current command segment (handles pipes)
+# Returns the text after the last pipe before cursor
+zvm_get_current_segment() {
+  local segment="${LBUFFER##*|}"
+  # Trim leading whitespace
+  segment="${segment#"${segment%%[![:space:]]*}"}"
+  echo "$segment"
+}
+
+# Extract the command name from a segment
+# Takes the first word of the segment
+zvm_parse_command() {
+  local segment
+  segment=$(zvm_get_current_segment)
+  echo "${segment%%[[:space:]]*}"
+}
+
+# Determine the man page to open, checking for subcommands
+# Input: $1 = command, $2 = current_segment
+# Output: man page name (e.g., "git-commit" or just "git")
+zvm_determine_man_page() {
+  local cmd="$1"
+  local segment="$2"
+  local man_page="$cmd"
+
+  local rest="${segment#*[[:space:]]}"
+  local potential_subcommand="${rest%%[[:space:]]*}"
+
+  # Check for subcommand man pages (e.g., git-commit, docker-run)
+  if [[ -n "$potential_subcommand" && ! "$potential_subcommand" =~ ^- ]]; then
+    if man -w "${cmd}-${potential_subcommand}" &>/dev/null; then
+      man_page="${cmd}-${potential_subcommand}"
+    fi
+  fi
+
+  echo "$man_page"
+}
+