docs: use pipe pattern for curl installer commands

Replace `sh -c "$(curl ...)"` with `curl ... | sh` across all
documentation. The subshell pattern breaks when users embed the
command inside other scripts (e.g. Dockerfiles using here-docs),
because the outer shell eagerly expands `$(curl ...)` before writing
the script to disk, mangling the installer contents.

The pipe pattern avoids this problem and is friendlier to further
scripting. For commands that pass arguments (--dry-run, --dev),
`sh -s --` is used to forward them through stdin.

README.md

@@ -208,7 +208,7 @@ If terminals, API keys, or config files are new to you, use the guided zero-back
 macOS / Linux:
 
 ```bash
-sh -c "$(curl -fsSL https://raw.githubusercontent.com/HKUDS/nanobot/main/scripts/install.sh)"
+curl -fsSL https://raw.githubusercontent.com/HKUDS/nanobot/main/scripts/install.sh | sh
 ```
 
 Windows PowerShell:
@@ -222,7 +222,7 @@ The default command installs or upgrades `nanobot-ai` from PyPI, then starts `na
 To preview the plan without changing your environment, pass `--dry-run`; combine it with `--dev` when you want to preview the main-branch install.
 
 ```bash
-sh -c "$(curl -fsSL https://raw.githubusercontent.com/HKUDS/nanobot/main/scripts/install.sh)" -- --dry-run
+curl -fsSL https://raw.githubusercontent.com/HKUDS/nanobot/main/scripts/install.sh | sh -s -- --dry-run
 ```
 
 ```powershell
@@ -232,7 +232,7 @@ sh -c "$(curl -fsSL https://raw.githubusercontent.com/HKUDS/nanobot/main/scripts
 To install the current `main` branch instead, pass `--dev`:
 
 ```bash
-sh -c "$(curl -fsSL https://raw.githubusercontent.com/HKUDS/nanobot/main/scripts/install.sh)" -- --dev
+curl -fsSL https://raw.githubusercontent.com/HKUDS/nanobot/main/scripts/install.sh | sh -s -- --dev
 ```
 
 ```powershell

docs/quick-start.md

@@ -23,7 +23,7 @@ Pick one install method.
 **One-command setup:**
 
 ```bash
-sh -c "$(curl -fsSL https://raw.githubusercontent.com/HKUDS/nanobot/main/scripts/install.sh)"
+curl -fsSL https://raw.githubusercontent.com/HKUDS/nanobot/main/scripts/install.sh | sh
 ```
 
 On Windows PowerShell:
@@ -37,7 +37,7 @@ The default command installs or upgrades `nanobot-ai` from PyPI, then starts `na
 To preview the plan without changing your environment, pass `--dry-run`; combine it with `--dev` when you want to preview the main-branch install.
 
 ```bash
-sh -c "$(curl -fsSL https://raw.githubusercontent.com/HKUDS/nanobot/main/scripts/install.sh)" -- --dry-run
+curl -fsSL https://raw.githubusercontent.com/HKUDS/nanobot/main/scripts/install.sh | sh -s -- --dry-run
 ```
 
 ```powershell
@@ -47,7 +47,7 @@ sh -c "$(curl -fsSL https://raw.githubusercontent.com/HKUDS/nanobot/main/scripts
 To install the current `main` branch instead, pass `--dev`:
 
 ```bash
-sh -c "$(curl -fsSL https://raw.githubusercontent.com/HKUDS/nanobot/main/scripts/install.sh)" -- --dev
+curl -fsSL https://raw.githubusercontent.com/HKUDS/nanobot/main/scripts/install.sh | sh -s -- --dev
 ```
 
 ```powershell

docs/start-without-technical-background.md

@@ -81,7 +81,7 @@ The easiest path is the one-command installer. It installs or upgrades nanobot,
 **macOS / Linux**
 
 ```bash
-sh -c "$(curl -fsSL https://raw.githubusercontent.com/HKUDS/nanobot/main/scripts/install.sh)"
+curl -fsSL https://raw.githubusercontent.com/HKUDS/nanobot/main/scripts/install.sh | sh
 ```
 
 **Windows PowerShell**
@@ -93,7 +93,7 @@ irm https://raw.githubusercontent.com/HKUDS/nanobot/main/scripts/install.ps1 | i
 These commands install the stable PyPI package. To preview what the installer would do without changing your environment, pass `--dry-run`:
 
 ```bash
-sh -c "$(curl -fsSL https://raw.githubusercontent.com/HKUDS/nanobot/main/scripts/install.sh)" -- --dry-run
+curl -fsSL https://raw.githubusercontent.com/HKUDS/nanobot/main/scripts/install.sh | sh -s -- --dry-run
 ```
 
 ```powershell
@@ -103,7 +103,7 @@ sh -c "$(curl -fsSL https://raw.githubusercontent.com/HKUDS/nanobot/main/scripts
 Use the development installer only when a maintainer asks you to test the current `main` branch:
 
 ```bash
-sh -c "$(curl -fsSL https://raw.githubusercontent.com/HKUDS/nanobot/main/scripts/install.sh)" -- --dev
+curl -fsSL https://raw.githubusercontent.com/HKUDS/nanobot/main/scripts/install.sh | sh -s -- --dev
 ```
 
 ```powershell

docs/troubleshooting.md

@@ -72,7 +72,7 @@ Use the same Python command for install checks and module fallback. On macOS/Lin
 | `No module named nanobot` | You are running a different Python than the one used for installation. Run `python -m pip show nanobot-ai`, `python3 -m pip show nanobot-ai`, or `py -m pip show nanobot-ai`, matching the command that installed nanobot. |
 | `pip is not available` | When the installer uses a virtual environment, it tries `python -m ensurepip --upgrade`. If that fails, install pip for that Python, or use a Python installer/distribution that includes pip. |
 | `externally-managed-environment` | Your system Python blocks global pip installs. Use the one-command installer, `uv tool install nanobot-ai`, `pipx install nanobot-ai`, or create a virtual environment; do not add `--break-system-packages` for nanobot. |
-| Installer chose the wrong Python | Set `PYTHON` before running the installer, such as `PYTHON=python3 sh -c "$(curl -fsSL https://raw.githubusercontent.com/HKUDS/nanobot/main/scripts/install.sh)"` or `$env:PYTHON="py"` before the PowerShell command. |
+| Installer chose the wrong Python | Set `PYTHON` before running the installer, such as `curl -fsSL https://raw.githubusercontent.com/HKUDS/nanobot/main/scripts/install.sh | PYTHON=python3 sh` or `$env:PYTHON="py"` before the PowerShell command. |
 | Editable source install does not update | From the repo root, run `python -m pip install -e .` again with the Python command used for development, then check `python -m nanobot --version` or `nanobot --version`. |
 | WebUI build tools missing | They are only needed for WebUI development. Packaged installs already include the WebUI bundle. |