<reasoning_content>
The user wants a basic job queue implementation in Python.
Requirements:
1. Class `JobQueue`
2. Methods: `add_job(job_id: str, data: dict) -> str`, `get_result(job_id: str) -> dict | None`
3. FIFO order processing
4. Store jobs internally until processed
5. Each job has a unique job_id returned when added
6. Write only Python code, no explanations.

I need to implement a thread-safe or at least basic queue. Since it's a "basic" job queue, I'll use `collections.deque` for FIFO ordering and a dictionary for storing job results/status. I'll also need a way to simulate or handle processing, but the prompt says "The queue should store jobs internally until they are processed". It doesn't specify how processing happens, but typically a job queue has a worker or a method to process jobs. I'll add a simple `process_next()` method or assume the user will call it, or I can make it process automatically? The example shows:
```python
queue = JobQueue()
job_id = queue.add_job("job1", {"task": "process_data"})
# After processing...
result = queue.get_result("job1")
```
This implies the queue might process jobs automatically or there's an implicit processing step. To keep it simple and standard, I'll implement a queue that stores jobs and results, and provide a method to process them, or I can just store them in a deque and simulate processing via a method. Actually, the prompt says "Jobs should be processed in FIFO order". I'll add a `process_next()` method or just assume the user will handle processing, but it's better to include a simple processing mechanism or at least the structure for it. Wait, the prompt says "Implement a basic job queue". I'll stick to the required methods and maybe add a `process()` method for completeness, or just store jobs in a deque and results in a dict.

Let's stick strictly to the requirements. I'll implement `add_job`, `get_result`, and maybe a `process_jobs()` or just store them. Actually, a job queue usually has a worker thread or a method to run jobs. I'll keep it simple: use `collections.deque` for the queue and a `dict` for results. I'll add a `process_next()` method that pops from the deque, simulates processing, and stores the result. Or I can just leave processing to the user, but the requirement says "Jobs should be processed in FIFO order". I'll implement a simple synchronous processor.

Wait, the example shows:
```python
queue = JobQueue()
job_id = queue.add_job("job1", {"task": "process_data"})
# After processing...
result = queue.get_result("job1")
```
This suggests that processing might be external or I should provide a way to process. I'll add a `process()` method that processes all pending jobs, or just store the jobs and let the user call a process method. To be safe, I'll implement a basic queue with a `process_next()` method, or just keep it simple with `add_job`, `get_result`, and maybe `process_all()`.

Actually, I can just implement the class with the required methods and a simple internal deque for jobs and a dict for results. I'll add a `process()` method that simulates processing for demonstration, or I can just store the jobs and assume the user will process them. But the requirement says "Jobs should be processed in FIFO order". I'll interpret this as: the queue maintains order, and I'll provide a `process()` method that pops and "executes" jobs (simulated by storing data as result).

Let's draft:
```python
import collections
import uuid

class JobQueue:
    def __init__(self):
        self._queue = collections.deque()
        self._results = {}
        
    def add_job(self, job_id: str, data: dict) -> str:
        self._queue.append((job_id, data))
        return job_id
        
    def get_result(self, job_id: str) -> dict | None:
        return self._results.get(job_id, None)
        
    def process_next(self):
        if self._queue:
            job_id, data = self._queue.popleft()
            # Simulate processing
            self._results[job_id] = {"status": "completed", "data": data}
            
    def process_all(self):
        while self._queue:
            self.process_next()
```

The prompt says "Write only the Python code, no explanations."
I'll refine it to match exactly the requirements. The type hint `dict | None` is Python 3.10+. I'll use `Optional[dict]` for broader compatibility or stick to `dict | None` as requested. The prompt uses `dict | None`, so I'll use that.

Wait, the prompt says "Each job has a unique job_id that is returned when added". The example shows `job_id = queue.add_job("job1", ...)`, so the user provides the job_id, or I generate one? The signature says `add_job(job_id: str, data: dict) -> str`, so the user passes it. I'll just store it.

I'll keep it simple. I won't overcomplicate with threading unless necessary. The prompt is basic.

Let's ensure it matches exactly:
```python
import collections
from typing import Optional

class JobQueue:
    def __init__(self):
        self._queue = collections.deque()
        self._results = {}

    def add_job(self, job_id: str, data: dict) -> str:
        self._queue.append((job_id, data))
        return job_id

    def get_result(self, job_id: str) -> dict | None:
        return self._results.get(job_id, None)

    def process_next(self) -> bool:
        if self._queue:
            job_id, data = self._queue.popleft()
            self._results[job_id] = {"status": "completed", "data": data}
            return True
        return False

    def process_all(self) -> None:
        while self._queue:
            self.process_next()
```

The prompt doesn't ask for process_next or process_all, but says "Jobs should be processed in FIFO order". I'll include a simple `process()` method to fulfill that, or I can just assume the queue itself processes jobs? Usually, a job queue has a worker. I'll stick to the above. It's safe.

Actually, I can make it even simpler. The requirement is just to implement the class with those two methods, and ensure FIFO order internally. I'll add a `process_jobs()` method for completeness.

Wait, the prompt says: "Implement a basic job queue in Python." and lists requirements. I'll just provide the class.

One thing: `dict | None` is valid in Python 3.10+. I'll use it as requested.

Let's verify the example usage:
```python
queue = JobQueue()
job_id = queue.add_job("job1", {"task": "process_data"})
# After processing...
result = queue.get_result("job1")
```
This implies that after calling `add_job`, the user might call a process method, or maybe the queue processes automatically? I'll add a `process()` method that processes all jobs, or just leave it as is. I think adding `process_all()` is fine.

I'll write the code concisely.

```python
import collections
from typing import Optional

class JobQueue:
    def __init__(self):
        self._queue = collections.deque()
        self._results = {}

    def add_job(self, job_id: str, data: dict) -> str:
        self._queue.append((job_id, data))
        return job_id

    def get_result(self, job_id: str) -> dict | None:
        return self._results.get(job_id, None)

    def process_next(self) -> bool:
        if self._queue:
            job_id, data = self._queue.popleft()
            self._results[job_id] = {"status": "completed", "data": data}
            return True
        return False

    def process_all(self) -> None:
        while self._queue:
            self.process_next()
```

Actually, I can simplify `get_result` return type to `Optional[dict]` for compatibility, but the prompt uses `dict | None`. I'll stick to `dict | None`.

Is there any need for thread safety? The prompt says "basic", so probably not. I'll skip threading unless specified.

One minor thing: The prompt says "Each job has a unique job_id that is returned when added". It might imply I should generate it if not provided, but the signature explicitly takes `job_id: str`. So I'll just return what's passed.

I'll output just the code as requested.

Final check of the prompt: "Write only the Python code, no explanations."
I will provide exactly the class implementation.

I'll make sure the type hints match exactly.
`dict | None` is fine.
I'll add `import collections` at the top.

Code:
```python
import collections

class JobQueue:
    def __init__(self):
        self._queue = collections.deque()
        self._results = {}

    def add_job(self, job_id: str, data: dict) -> str:
        self._queue.append((job_id, data))
        return job_id

    def get_result(self, job_id: str) -> dict | None:
        return self._results.get(job_id, None)

    def process_next(self) -> bool:
        if self._queue:
            job_id, data = self._queue.popleft()
            self._results[job_id] = {"status": "completed", "data": data}
            return True
        return False

    def process_all(self) -> None:
        while self._queue:
            self.process_next()
```

This satisfies all requirements. FIFO via deque. Stores internally. Returns job_id. get_result returns dict or None. I'll output this.
One thing: `dict | None` requires Python 3.10+. I'll keep it as is since the prompt used it.
I'll remove comments to keep it clean.
Ready.✅
Output matches response. 
Proceeds. 
Self-Correction/Refinement during thought: 
The prompt says "Each job has a unique job_id that is returned when added". It might be better to generate the ID if not provided, but the signature is fixed. I'll stick to the signature.
Also, maybe I should just include `process()` as a method that the example implies? The example has a comment `# After processing...`. It's fine.
I'll output the code exactly.
All good. 
Output generation. 
```python
import collections

class JobQueue:
    def __init__(self):
        self._queue = collections.deque()
        self._results = {}

    def add_job(self, job_id: str, data: dict) -> str:
        self._queue.append((job_id, data))
        return job_id

    def get_result(self, job_id: str) -> dict | None:
        return self._results.get(job_id, None)

    def process_next(self) -> bool:
        if self._queue:
            job_id, data = self._queue.popleft()
            self._results[job_id] = {"status": "completed", "data": data}
            return True
        return False

    def process_all(self) -> None:
        while self._queue:
            self.process_next()
```
This is correct and matches requirements. I will present it. 
Note: I'll make sure the type hint `dict | None` is used as requested. If Python version compatibility is a concern, `typing.Optional` is safer, but I'll stick to the prompt's syntax. Actually, `dict | None` is standard in modern Python. I'll keep it.
Done. 
Output matches the refined code. 
Proceeds. 
[Output Generation] -> *Proceeds*

</reasoning_content>

<content>
```python
import collections

class JobQueue:
    def __init__(self):
        self._queue = collections.deque()
        self._results = {}

    def add_job(self, job_id: str, data: dict) -> str:
        self._queue.append((job_id, data))
        return job_id

    def get_result(self, job_id: str) -> dict | None:
        return self._results.get(job_id, None)

    def process_next(self) -> bool:
        if self._queue:
            job_id, data = self._queue.popleft()
            self._results[job_id] = {"status": "completed", "data": data}
            return True
        return False

    def process_all(self) -> None:
        while self._queue:
            self.process_next()
```
</content>