docs: say what Apple's Python 3.9 does to the install command

On a Mac with no other Python, `python3` is 3.9.6. `runorca` needs 3.10 or
newer, so the lab's `pip install -r requirements.txt` stops at
`No matching distribution found for runorca==0.3.0`, which does not mention
Python. Both courses now say to check `python3 --version` first, and both
troubleshooting pages list the symptom.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_014Nq3n2MeC9XrC31wYfdjZv

Author: sijie

docs/before-you-arrive.md

@@ -45,6 +45,11 @@ source .venv/bin/activate        # Git Bash on Windows: source .venv/Scripts/act
 pip install -r requirements.txt
 ```
 
+`python3 --version` has to say 3.11 or newer. On macOS, Apple's own `python3`
+is 3.9, and with it `pip` stops at
+`No matching distribution found for runorca`. Install a newer Python and name it
+in the second line, for example `python3.13 -m venv .venv`.
+
 **TypeScript**
 
 ```bash

labs/cloud/00-set-up.md

@@ -45,6 +45,11 @@ source .venv/bin/activate        # Git Bash on Windows: source .venv/Scripts/act
 pip install -r requirements.txt
 ```
 
+`python3 --version` has to say 3.11 or newer. On macOS, Apple's own `python3`
+is 3.9, and with it `pip` stops at
+`No matching distribution found for runorca`. Install a newer Python and name it
+in the second line, for example `python3.13 -m venv .venv`.
+
 **TypeScript** (Node.js 20 or newer)
 
 ```bash

labs/cloud/troubleshooting.md

@@ -13,6 +13,7 @@ Still stuck after two tries? Raise your hand.
 
 | Symptom | Fix |
 |---|---|
+| `pip install -r requirements.txt`: `No matching distribution found for runorca==0.3.0` | The `python3` that made your virtual environment is older than the course needs: on macOS, Apple's own is 3.9. Install Python 3.11 or newer, then make the environment again with it. In `python/`: `rm -rf .venv`, then the install commands from Lab 0 with that Python's name in place of `python3`, for example `python3.13 -m venv .venv`. |
 | Doctor: `Agent Engine HTTP 401/403` | The key was rejected. A key created before its permissions must be re-created: ask a facilitator. |
 | Doctor: `Kafka ... authentication` | `SN_SERVICE_ACCOUNT` must be the full principal, `<name>@<org>.auth.streamnative.cloud`; `SN_API_KEY` is the raw key. |
 | Doctor: `Kafka   security.login_events: not found` | The topic is not there yet. Create it and load it: Lab 0, step 3. |

labs/local/00-set-up.md

@@ -18,6 +18,11 @@ part of the stack answers and the topic holds 246 logins.
   |---|---|
   | `cd python && python3 -m venv .venv && source .venv/bin/activate && pip install -r requirements.txt` | `cd typescript && npm install` |
 
+  For Python, `python3 --version` has to say 3.11 or newer. On macOS, Apple's
+  own `python3` is 3.9, and with it `pip` stops at
+  `No matching distribution found for runorca`. Install a newer Python and name
+  it in the command, for example `python3.13 -m venv .venv`.
+
   The CLI path needs only `ork` and `jq` for the labs, plus one of the two
   above for the doctor, the seeder, and the injector.
 - Keep two terminals open: one in your path's folder (`cli/`, `python/` or

labs/local/troubleshooting.md

@@ -15,6 +15,7 @@ Each failed line prints its fix.
 |---|---|
 | `docker compose ... up` fails with a port already in use | Another program has one of the ports the stack publishes on `127.0.0.1`: 29092 (Kafka), 18081 (schema registry), 4566 and 5691 (RisingWave), 8000 (MCP). Stop that program, run `local/down.sh`, then run the `up` command again. Running it again without `local/down.sh` is not enough: Docker brings the container whose port was taken back without its network. The ports are fixed: the broker tells its clients to come back to `127.0.0.1:29092`, and `local/write-env.sh` writes these ports into `.env`. |
 | `local/engine.sh` fails because a port is taken (`Bind for 0.0.0.0:8080 failed: port is already allocated`) | Another program has a port the engine publishes on `127.0.0.1`: 8080 (the registry) or 18082. If it is a container, `docker ps` shows which: look for `:8080->` under PORTS. Stop that program and run `local/engine.sh` again. If the port is 8080 and you want to keep that program running, move the registry instead: `export ORCA_LOCAL_REGISTRY_PORT=18080`, run `local/engine.sh` again, then `local/write-env.sh` so `.env` has the new address. Export it in every terminal you run `local/engine.sh` from: a run without it goes back to 8080. |
+| `pip install -r requirements.txt`: `No matching distribution found for runorca==0.3.0` | The `python3` that made your virtual environment is older than the course needs: on macOS, Apple's own is 3.9. Install Python 3.11 or newer, then make the environment again with it. In `python/`: `rm -rf .venv`, then the install command from Lab 0 with that Python's name in place of `python3`, for example `python3.13 -m venv .venv`. |
 | `local/engine.sh`: `ANTHROPIC_API_KEY is not set in this shell` | `export ANTHROPIC_API_KEY=<your key>` in the terminal where you run the script. The engine reads the key only when it starts. |
 | `local/engine.sh`: `FAIL  the model provider accepts that key` | The fix under that line says why. `the provider answered 401` (or `403`): the provider refuses the key the engine started with. `export ANTHROPIC_API_KEY=<a key that works>`, then `local/engine.sh`. `the engine cannot reach https://api.anthropic.com`: the engine has no way out to the provider. Check your network, then `local/engine.sh --check`. |
 | `local/engine.sh`: `bootstrap refused: an organization already exists` | The engine's volumes exist but its keys in `.lab/ork` are gone. Start over: `local/down.sh --reset`, then Lab 0. |