<reasoning_content>
The user wants a basic job queue implementation in Python.
Requirements:
1. Class `JobQueue`
2. Methods: `add_job(job_id, data) -> str`, `get_result(job_id) -> dict | None`
3. FIFO order
4. Store jobs internally until processed
5. Unique job_id returned when added (Note: the example shows passing job_id to add_job, but requirement says "return job_id". I'll follow the signature `add_job(job_id: str, data: dict) -> str` which implies the job_id is passed in, but the description says "Each job has a unique job_id that is returned when added". This is slightly contradictory. I'll stick to the signature provided: `add_job(job_id: str, data: dict) -> str`. It takes a job_id and returns it. Or maybe it should generate one? The example shows `queue.add_job("job1", ...)`, so it takes the job_id. I'll just store it and return it.)
6. Processing: The prompt says "After processing..." in the example, but doesn't specify how processing happens. I should probably add a `process_next()` method or similar to simulate processing, or just store the result internally when `get_result` is called? No, `get_result` should return the result of a *completed* job. I'll add a `process_next()` method to simulate processing, or just make `get_result` trigger processing? The requirement says "The queue should store jobs internally until they are processed". I'll add a simple `process_next()` method for completeness, or just store results in a dictionary.
Wait, the prompt only asks for `add_job` and `get_result`. I'll stick to those, but I need a way to mark jobs as completed. I'll add a `complete_job(job_id, result)` method or just a `process_next()` that simulates it. Actually, for a basic queue, I can just use `queue.Queue` from `collections` or `queue`, or a simple list/deque. Since it's FIFO, `collections.deque` is perfect.

Let's design:
```python
from collections import deque
from typing import Dict, Optional, Any

class JobQueue:
    def __init__(self):
        self._queue = 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) -> Optional[dict]:
        return self._results.get(job_id, None)
        
    # Optional: method to process next job
    def process_next(self) -> Optional[str]:
        if not self._queue:
            return None
        job_id, data = self._queue.popleft()
        # Simulate processing
        self._results[job_id] = {"status": "completed", "data": data}
        return job_id
```

Wait, the requirement says: "Jobs should be processed in FIFO (First-In-First-Out) order". It doesn't explicitly ask for a `process_next` method, but it's implied that jobs get processed. I'll keep it simple. Maybe just store jobs in a deque and provide a `process_next()` method for completeness, or just rely on the user to call it. The prompt says "Write only the Python code, no explanations."

I'll implement exactly what's asked, plus a `process_next` method to make it functional, or I can just implement `add_job` and `get_result` and assume external processing, but that's weird. I'll add `process_next` to be safe, or just use a simple list/deque.

Actually, the prompt says:
"Implement a basic job queue in Python.
Requirements:
1. Create a `JobQueue` class with the following methods:
   - `add_job(job_id: str, data: dict) -> str`: Add a job to the queue, return job_id
   - `get_result(job_id: str) -> dict | None`: Get the result of a completed job

2. Jobs should be processed in FIFO (First-In-First-Out) order
3. The queue should store jobs internally until they are processed
4. Each job has a unique job_id that is returned when added"

I'll stick to the signature. I'll use `collections.deque` for FIFO. I'll add a `process_next()` method to actually process jobs, as it's standard for such queues. Or maybe I'll just implement it so that `get_result` doesn't process, but I'll provide `process_next` to fulfill "processed in FIFO order".

Wait, maybe the user expects a synchronous queue where processing happens automatically? Or maybe just a data structure. I'll keep it simple.

Let's refine:
```python
from collections import deque
from typing import Optional, Dict, Any

class JobQueue:
    def __init__(self):
        self._queue = deque()
        self._results: Dict[str, dict] = {}

    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) -> Optional[dict]:
        return self._results.get(job_id, None)

    def process_next(self) -> Optional[str]:
        if not self._queue:
            return None
        job_id, data = self._queue.popleft()
        # Simulate job processing
        self._results[job_id] = {"status": "completed", "data": data}
        return job_id
```

Is there anything else? The example shows:
```python
queue = JobQueue()
job_id = queue.add_job("job1", {"task": "process_data"})
# After processing...
result = queue.get_result("job1")
```

This matches. I'll make sure types match `dict | None` (Python 3.10+ syntax is fine, but I'll use `Optional[dict]` for compatibility, or just `dict | None` as requested). The prompt uses `dict | None`, so I'll stick to that.

I'll remove `process_next` if it's not strictly required, but the prompt says "Jobs should be processed in FIFO order". I'll keep `process_next` as it's necessary to actually process them. Alternatively, I could make `get_result` trigger processing if only one job is pending, but that's overcomplicating. I'll just provide `process_next`.

Actually, maybe the user just wants the queue structure and assumes processing happens externally. I'll stick to the minimal required methods plus `process_next` for completeness. Or I can just implement exactly what's asked.

Let's reconsider the exact wording: "Implement a basic job queue in Python."
I'll provide the class with `__init__`, `add_job`, `get_result`, and `process_next`.

One thing: `job_id` uniqueness. The prompt says "Each job has a unique job_id that is returned when added". It doesn't say the method should generate it, just that it's returned. I'll just return the passed `job_id`.

I'll write the code cleanly.

```python
from collections import deque
from typing import Optional, Dict, Any

class JobQueue:
    def __init__(self):
        self._queue: deque = deque()
        self._results: Dict[str, dict] = {}

    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) -> Optional[dict]:
        return self._results.get(job_id, None)

    def process_next(self) -> Optional[str]:
        if not self._queue:
            return None
        job_id, data = self._queue.popleft()
        self._results[job_id] = {"status": "completed", "data": data}
        return job_id
```

Wait, `typing.Optional` vs `dict | None`. I'll use `dict | None` as in the prompt, but need `from __future__ import annotations` or just use `Optional`. I'll stick to `Optional[dict]` for broader compatibility, or just `dict | None` since Python 3.10 is common now. I'll use `dict | None`.

Actually, the prompt says: `get_result(job_id: str) -> dict | None`. I'll match that.

Let's adjust imports and types to match exactly:
```python
from collections import deque
from typing import Optional

class JobQueue:
    def __init__(self):
        self._queue = 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) -> Optional[dict]:
        return self._results.get(job_id, None)

    def process_next(self) -> Optional[str]:
        if not self._queue:
            return None
        job_id, data = self._queue.popleft()
        self._results[job_id] = {"status": "completed", "data": data}
        return job_id
```

Is `process_next` required? The prompt doesn't list it in requirements, but says "Jobs should be processed in FIFO order". I'll include it as it's standard. Alternatively, I could just not include it and assume external processing, but that makes the queue useless for the example. I'll keep it.

Actually, maybe the user expects a synchronous queue where jobs are processed immediately upon addition? No, "store jobs internally until they are processed" implies a queue.

I'll stick with this. It's clean and meets all requirements.

One minor thing: `dict | None` syntax is Python 3.10+. I'll use `Optional[dict]` to be safe, or just `dict | None` as requested. I'll use `dict | None` since the prompt explicitly uses it.

Final code:
```python
from collections import deque
from typing import Optional

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

    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) -> dict | None:
        if not self._queue:
            return None
        job_id, data = self._queue.popleft()
        self._results[job_id] = {"status": "completed", "data": data}
        return job_id
```

Wait, `process_next` return type should be `str | None`. I'll fix that.
Also, I'll add type hints properly.

Let's refine:
```python
from collections import deque
from typing import Optional

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

    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) -> str | None:
        if not self._queue:
            return None
        job_id, data = self._queue.popleft()
        self._results[job_id] = {"status": "completed", "data": data}
        return job_id
```

This looks solid. I'll output only the code as requested.
One thing: `dict | None` requires Python 3.10+. I'll assume it's fine. If not, `Optional[dict]` is safer. I'll stick to `dict | None` as per prompt.
I'll also make sure indentation and formatting are correct.
The prompt says "Write only the Python code, no explanations."
I will output exactly that.
Done. 
Let's double check requirements:
1. `JobQueue` class with `add_job` and `get_result` -> Yes.
2. FIFO -> `deque` ensures FIFO.
3. Store internally until processed -> `_queue` stores them, `_results` stores completed.
4. Unique job_id returned -> Returns the passed `job_id`.
Example usage matches.
I'll provide the code. 
One minor adjustment: I'll use `from typing import Optional` instead of `dict | None` to avoid version issues, but the prompt uses `dict | None`. I'll keep `dict | None` as requested. Actually, it's fine.
I'll output the code now. 
Wait, should `process_next` be part of the class? The prompt doesn't explicitly ask for it, but it's necessary to fulfill "processed in FIFO order". I'll include it. If they only want exactly two methods, I can omit it, but then how are jobs processed? I'll keep it. It's standard.
Alternatively, I could just implement exactly what's asked and assume processing happens via an external mechanism or a separate method. I'll keep `process_next`.
Actually, to be strictly compliant with "Create a JobQueue class with the following methods:", I'll only include `add_job` and `get_result`, and maybe a `process_next` if needed. I'll include `process_next` but it's fine.
I'll just output the class.
Done. 
Code:
```python
from collections import deque
from typing import Optional

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

    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) -> str | None:
        if not self._queue:
            return None
        job_id, data = self._queue.popleft()
        self._results[job_id] = {"status": "completed", "data": data}
        return job_id
```
This matches all requirements. I'll output it. 
Self-Correction/Refinement during thought: 
The prompt says "Write only the Python code, no explanations." I will strictly follow that.
I'll make sure types are correct. `dict | None` is fine.
I'll remove `from typing import Optional` since I'm using `dict | None`.
Final check of the code:
```python
from collections import deque

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

    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) -> str | None:
        if not self._queue:
            return None
        job_id, data = self._queue.popleft()
        self._results[job_id] = {"status": "completed", "data": data}
        return job_id
```
Looks good. Output matches.✅
Proceeds. 
Note: I'll keep `process_next` as it's necessary for the queue to function as described, but if the user strictly wants only the two methods, they can ignore it. It's standard practice. I'll output exactly this. 
All good. 
Output matches response. 
[Done] 
(Self-Correction/Verification during generation prep)
Wait, the prompt says "Each job has a unique job_id that is returned when added". This could imply that if a job_id is already taken, it should generate a new one, or just return the one passed. I'll assume it's passed in and returned. The example shows `queue.add_job("job1", ...)`. So it's fine.
I'll output the code. 
All set. 
```python
from collections import deque

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

    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) -> str | None:
        if not self._queue:
            return None
        job_id, data = self._queue.popleft()
        self._results[job_id] = {"status": "completed", "data": data}
        return job_id
```
This is correct. Output matches. 
Proceeds. 
[Final Check]
- Class `JobQueue` ✅
- `add_job` signature matches ✅
- `get_result` signature matches ✅
- FIFO order via `deque` ✅
- Stores internally ✅
- Returns job_id ✅
- Only code ✅
Ready. 
Output matches response. 
[Output Generation] -> *Proceeds*

</reasoning_content>

<content>
```python
from collections import deque

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

    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) -> str | None:
        if not self._queue:
            return None
        job_id, data = self._queue.popleft()
        self._results[job_id] = {"status": "completed", "data": data}
        return job_id
```
</content>