docs(cli): add molecli shell completion guide (#79)

Pair PR: molecule-cli#5
- Adds new guides/molecli-shell-completion.md with bash/zsh/fish/PowerShell
  install instructions for molecli tab completion (Cobra-generated)
- Adds entry to guides/index.md under new "CLI Tooling" section
- Links to molecule-cli#5 for implementation details

Co-authored-by: Molecule AI Documentation Specialist <documentation-specialist@agents.moleculesai.app>

content/docs/guides/index.md

@@ -9,6 +9,10 @@ Step-by-step guides for common Molecule AI integrations and configurations.
 
 - [Quickstart](/docs/quickstart) — Deploy your first AI agent in under 5 minutes.
 
+## CLI Tooling
+
+- [molecli Shell Completion](/docs/guides/molecli-shell-completion) — Enable tab completion for the `molecule` CLI (`molecli`) TUI dashboard in bash, zsh, fish, and PowerShell.
+
 ## Remote Agents
 
 - [External Agent Registration](/docs/guides/external-agent-registration) — Register agents running outside the platform Docker network (on laptops, cloud VMs, edge devices) as first-class workspaces with per-workspace bearer tokens.

content/docs/guides/molecli-shell-completion.md

@@ -0,0 +1,93 @@
+---
+title: molecli Shell Completion
+description: Enable tab completion for the molecli (molecule-cli) TUI dashboard in bash, zsh, fish, and PowerShell.
+---
+
+# molecli Shell Completion
+
+The `molecule` CLI (`molecli`) supports shell completion for bash, zsh, fish, and PowerShell. Completion scripts are auto-generated by [Cobra](https://github.com/spf13/cobra) and cover all subcommands and flags.
+
+## Install
+
+### bash
+
+Add to `~/.bashrc` or `~/.bash_completion.d/`:
+
+```bash
+source <(molecule completion bash)
+```
+
+Or source from your profile:
+
+```bash
+# In ~/.bash_profile or ~/.bashrc
+[[ -f ~/.bash_completion ]] && source ~/.bash_completion
+source <(molecule completion bash)
+```
+
+### zsh
+
+Add to `~/.zshrc`:
+
+```bash
+autoload -U compinit && compinit
+autoload -Uz bashcompinit && bashcompinit
+source <(molecule completion zsh)
+compdef _molecule molecule
+```
+
+Completion will activate automatically after restarting your shell or running `source ~/.zshrc`.
+
+### fish
+
+```fish
+molecule completion fish | source
+```
+
+To persist across sessions, add the line above to `~/.config/fish/config.fish`.
+
+### PowerShell
+
+Add to your PowerShell profile (`$PROFILE`):
+
+```powershell
+molecule completion powershell | Out-String | Invoke-Expression
+```
+
+To find and edit your profile:
+```powershell
+Split-Path $PROFILE
+code $PROFILE  # or your preferred editor
+```
+
+## Supported Shells
+
+| Shell | Flag | Install target |
+|-------|------|----------------|
+| bash | `bash` | `~/.bashrc` |
+| zsh | `zsh` | `~/.zshrc` |
+| fish | `fish` | `~/.config/fish/config.fish` |
+| PowerShell | `powershell` | `$PROFILE` |
+
+## Verifying
+
+After sourcing, test by typing a partial command:
+
+```bash
+molecule <TAB><TAB>
+```
+
+You should see available subcommands: `completion`, `workspace`, `config`, etc.
+
+## Reference
+
+```
+molecule completion [bash|zsh|fish|powershell]
+```
+
+- `bash` — Bash completions (~/.bashrc)
+- `zsh` — Zsh completions with compdef (~/.zshrc)
+- `fish` — Fish shell completions (~/.config/fish/completions)
+- `powershell` — PowerShell completions ($PROFILE)
+
+See [`molecule-cli` PR #5](https://github.com/Molecule-AI/molecule-cli/pull/5) for implementation details.