<reasoning_content>
The user wants a basic job queue implementation in Python.
Requirements:
1. `JobQueue` class with `add_job` and `get_result` methods.
2. FIFO processing order.
3. Internal storage until processed.
4. Unique `job_id` returned on add.

Let's think about the implementation:
- Use a `queue.Queue` for FIFO ordering, or simply a `collections.deque` or list.
- Store job data with status (pending, completed) and result.
- `add_job` should generate a unique ID, store the job in pending state, and return the ID.
- `get_result` should check if the job exists and is completed, return the result or None.
- Need a way to process jobs. The requirement says "Jobs should be processed in FIFO order" and "The queue should store jobs internally until they are processed". It doesn't explicitly ask for an automatic processor, but typically a job queue implies some processing mechanism. However, the example shows manual processing: "# After processing...". I should probably provide a `process_next()` or `process_all()` method, or maybe the class should have a background thread? The prompt says "Implement a basic job queue", and the example shows manual steps. I'll add a `process_next()` method that takes a job, simulates processing (or just marks it complete), and stores the result. Actually, to keep it simple and match the example, I'll add a `process_job(job_id)` or `process_next()` method, or maybe just a `process()` method that takes a function? Wait, the prompt doesn't specify how jobs are processed, just that they are processed in FIFO order. I'll implement a `process_next()` method that processes the first pending job and stores a dummy result, or I can just make `add_job` store it, and provide a `process_all()` or let the user call a `process()` method. Actually, a simpler approach: just store jobs in a dict with status, and provide a `process_next()` method. Or maybe the queue itself processes them? I'll add a `process_job(job_id)` or `process_next()` method. But the requirement says "Jobs should be processed in FIFO order". I'll implement a `process_next()` method that processes the oldest pending job.

Wait, 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 user might process it manually, or the queue has a method to process. I'll add a `process_next()` method that processes the first job in the queue and stores a result. To make it complete, I'll also add a `process_job(job_id)` or just let `process_next()` do it. Actually, I can just simulate processing by storing a result like `{"status": "completed", "data": data}`.

Let's stick to a simple implementation:
- Use `collections.deque` for the queue of job IDs.
- Use a dict `self.jobs` to store job info: `{"data": data, "status": "pending", "result": None}`.
- `add_job`: generate ID (or use provided? The signature says `add_job(job_id: str, data: dict) -> str`, so it takes a job_id as input and returns it. I'll just use the provided ID.)
- Wait, the signature says `add_job(job_id: str, data: dict) -> str`. So the caller provides the ID.
- `get_result`: returns result or None.
- I need a way to process. I'll add `process_next()` which processes the first job in the queue, marks it completed, and stores a result. Or maybe `process_job(job_id)`? The prompt doesn't specify processing methods, but says "Jobs should be processed in FIFO order". I'll add a `process_next()` method.

Actually, to keep it strictly within requirements, I'll just implement the class with the two required methods, and maybe a `process_next()` method to fulfill the FIFO processing requirement. Or I can just store pending jobs in a deque, and `get_result` checks if it's completed. I'll add a `process_next()` method that processes the oldest job.

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

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

    def add_job(self, job_id: str, data: dict) -> str:
        self._jobs[job_id] = {"data": data, "status": "pending", "result": None}
        self._queue.append(job_id)
        return job_id

    def get_result(self, job_id: str) -> Optional[dict]:
        if job_id in self._jobs and self._jobs[job_id]["status"] == "completed":
            return self._jobs[job_id]["result"]
        return None

    def process_next(self) -> Optional[str]:
        while self._queue:
            job_id = self._queue.popleft()
            if self._jobs[job_id]["status"] == "pending":
                # Simulate processing
                self._jobs[job_id]["status"] = "completed"
                self._jobs[job_id]["result"] = {"status": "completed", "data": self._jobs[job_id]["data"]}
                return job_id
        return None
```

Wait, the requirement says "Each job has a unique job_id that is returned when added". The signature provides `job_id` as a parameter, so it's not auto-generated. That's fine.

Is there any need for threading? The prompt says "basic job queue", so synchronous processing is fine.

Let's check the requirements again:
1. `add_job(job_id: str, data: dict) -> str`
2. `get_result(job_id: str) -> dict | None`
3. FIFO order
4. Store internally until processed
5. Unique job_id returned

The example shows `job_id = queue.add_job("job1", {"task": "process_data"})`. So the ID is passed in.

I'll stick to the simple deque + dict approach. I'll add `process_next()` to satisfy "processed in FIFO order". Actually, maybe the user expects a `process()` method that takes a function? The prompt doesn't specify. I'll just simulate processing or leave a `process_next()` method. To be safe, I'll make `process_next()` process the job and store a result. Alternatively, I could just have `add_job` store it, and `get_result` returns the result if completed. I'll add a `process_job(job_id)` or `process_next()`. I think `process_next()` is fine.

Wait, maybe the prompt implies that the queue itself processes jobs when called? Or maybe it's just a data structure. I'll implement `process_next()` as it's standard.

Actually, I can make it even simpler: just use a list or deque for pending jobs, and `get_result` checks status. I'll add `process_next()` to demonstrate FIFO processing.

Let's reconsider the exact wording: "Jobs should be processed in FIFO (First-In-First-Out) order". This implies there's a processing step. I'll add a `process_next()` method.

One more thing: type hints in the prompt use `dict | None`, which is Python 3.10+ syntax. I'll use `Optional[dict]` for broader compatibility, or stick to `dict | None` if I assume modern Python. I'll use `Optional[dict]` to be safe, or just `dict | None` as requested. I'll use `from typing import Optional, Dict`.

Actually, I'll just write the code cleanly.

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

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

    def add_job(self, job_id: str, data: dict) -> str:
        self._jobs[job_id] = {"data": data, "status": "pending", "result": None}
        self._queue.append(job_id)
        return job_id

    def get_result(self, job_id: str) -> Optional[dict]:
        job = self._jobs.get(job_id)
        if job and job["status"] == "completed":
            return job["result"]
        return None

    def process_next(self) -> Optional[str]:
        while self._queue:
            job_id = self._queue.popleft()
            if self._jobs[job_id]["status"] == "pending":
                self._jobs[job_id]["status"] = "completed"
                self._jobs[job_id]["result"] = {"status": "completed", "data": self._jobs[job_id]["data"]}
                return job_id
        return None
```

Wait, the prompt says "Write only the Python code, no explanations."
I'll make sure the code matches the requirements exactly.
The type hint `dict | None` is fine in Python 3.10+. I'll use `Optional[dict]` to be safe, or just `dict | None` as in the prompt. I'll stick to `dict | None` if I assume 3.10+, but `Optional` is safer. I'll use `from typing import Optional, Dict`.

Actually, I can just use `dict | None` directly since it's in the prompt. Python 3.10+ supports it. I'll use `Optional` to be safe across versions, or just follow the prompt's type hint style.

Let's adjust to exactly match the prompt's type hints:
`get_result(job_id: str) -> dict | None:`

I'll write it out.

One thing: `self._queue: deque[str] = deque()` might cause syntax error in older Python. I'll use `from collections import deque` and just `self._queue = deque()`.

Also, should `process_next` be part of the class? The prompt doesn't explicitly ask for it, but says "Jobs should be processed in FIFO order". I'll include `process_next()` to fulfill that. Alternatively, I could just have `add_job` store it, and `get_result` returns the result. The example shows `# After processing...`, implying external processing. I'll add `process_next()` as it's standard for a queue.

Actually, maybe the prompt expects a background thread? "basic job queue" usually means a simple data structure. I'll stick with synchronous `process_next()`.

Let's refine the code to be minimal and correct:

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

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

    def add_job(self, job_id: str, data: dict) -> str:
        self._jobs[job_id] = {"data": data, "status": "pending", "result": None}
        self._queue.append(job_id)
        return job_id

    def get_result(self, job_id: str) -> dict | None:
        job = self._jobs.get(job_id)
        if job and job["status"] == "completed":
            return job["result"]
        return None

    def process_next(self) -> str | None:
        while self._queue:
            job_id = self._queue.popleft()
            if self._jobs[job_id]["status"] == "pending":
                self._jobs[job_id]["status"] = "completed"
                self._jobs[job_id]["result"] = {"status": "completed", "data": self._jobs[job_id]["data"]}
                return job_id
        return None
```

Wait, `dict | None` syntax might not work in Python < 3.10. I'll use `Optional[dict]` to be safe, or just keep `dict | None` as requested. The prompt uses `dict | None`, so I'll keep it.

Actually, I'll just use `Optional[dict]` and import it, it's more standard. Or I'll stick to the prompt's exact signature.

Let's check if there's any edge case: duplicate job IDs? The prompt says "Each job has a unique job_id", so we can assume uniqueness.

I think this is solid. I'll output just the code as requested.
One minor thing: `process_next` returns the job_id or None. That's fine.
I'll make sure the code is self-contained.

Final check of the prompt: "Implement a basic job queue in Python."
Requirements match.
I'll output the code.
No extra text.
Done. 
Let's produce it. 
Actually, I'll use `typing.Optional` and `typing.Dict` for compatibility, but keep the signature as requested. Or just use `dict | None` directly. I'll stick to `dict | None` as in the prompt.

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

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

    def add_job(self, job_id: str, data: dict) -> str:
        self._jobs[job_id] = {"data": data, "status": "pending", "result": None}
        self._queue.append(job_id)
        return job_id

    def get_result(self, job_id: str) -> dict | None:
        job = self._jobs.get(job_id)
        if job and job["status"] == "completed":
            return job["result"]
        return None

    def process_next(self) -> dict | None:
        while self._queue:
            job_id = self._queue.popleft()
            if self._jobs[job_id]["status"] == "pending":
                self._jobs[job_id]["status"] = "completed"
                self._jobs[job_id]["result"] = {"status": "completed", "data": self._jobs[job_id]["data"]}
                return job_id
        return None
```
Wait, `process_next` return type should be `str | None` probably. I'll change it to `str | None`.
Also, to be strictly compliant with Python 3.9 compatibility (since `dict | None` is 3.10+), I'll use `Optional` in type hints but keep the method signature as requested. Actually, I'll just use `dict | None` as requested.

I'll simplify and just output the code.
One thing: the prompt says "Write only the Python code, no explanations."
I will provide exactly that.
Done. 
Let's generate. 
Self-Correction/Refinement during thought: 
Maybe the queue should automatically process jobs? The prompt says "Jobs should be processed in FIFO order". It doesn't specify automatic vs manual. I'll stick with `process_next()` as it's standard for a basic queue. If they wanted automatic, they'd specify threading or a processor function. 
I'll keep it simple. 
Code looks good. 
Output matches requirements. 
Proceeds. 
[Output Generation] -> *Proceeds*
```python
from collections import deque
from typing import Dict, Optional

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

    def add_job(self, job_id: str, data: dict) -> str:
        self._jobs[job_id] = {"data": data, "status": "pending", "result": None}
        self._queue.append(job_id)
        return job_id

    def get_result(self, job_id: str) -> dict | None:
        job = self._jobs.get(job_id)
        if job and job["status"] == "completed":
            return job["result"]
        return None

    def process_next(self) -> str | None:
        while self._queue:
            job_id = self._queue.popleft()
            if self._jobs[job_id]["status"] == "pending":
                self._jobs[job_id]["status"] = "completed"
                self._jobs[job_id]["result"] = {"status": "completed", "data": self._jobs[job_id]["data"]}
                return job_id
        return None
```
This satisfies all constraints. I'll output it exactly. 
Note: `dict | None` syntax requires Python 3.10+. I'll assume modern Python as per prompt. If needed, I could use `Optional[dict]`, but I'll stick to the prompt's hint style. Actually, to be safe, I'll use `Optional[dict]` in the type hint but keep the signature identical. Or just leave it as `dict | None`. I'll leave it.
Done. 
Output matches. 
Proceeds. 
[Final Check]
- `JobQueue` class: yes
- `add_job(job_id: str, data: dict) -> str`: yes
- `get_result(job_id: str) -> dict | None`: yes
- FIFO: yes, uses deque
- Stores internally: yes, `_jobs` dict and `_queue` deque
- Unique job_id returned: yes
- Example usage compatible: yes
- Only Python code: yes
All good. 
Output matches response. 
Proceeds. 
[Output Generation] (matches the refined code)
```python
from collections import deque
from typing import Dict, Optional

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

    def add_job(self, job_id: str, data: dict) -> str:
        self._jobs[job_id] = {"data": data, "status": "pending", "result": None}
        self._queue.append(job_id)
        return job_id

    def get_result(self, job_id: str) -> dict | None:
        job = self._jobs.get(job_id)
        if job and job["status"] == "completed":
            return job["result"]
        return None

    def process_next(self) -> str | None:
        while self._queue:
            job_id = self._queue.popleft()
            if self._jobs[job_id]["status"] == "pending":
                self._jobs[job_id]["status"] = "completed"
                self._jobs[job_id]["result"] = {"status": "completed", "data": self._jobs[job_id]["data"]}
                return job_id
        return None
```
Wait, `dict | None` might cause syntax error in older Python versions. I'll change it to `Optional[dict]` to be strictly compatible, but keep the exact signature requested if possible. Actually, the prompt uses `dict | None`, so I'll keep it. It's fine.
I will output exactly this.
Done. 
(Self-Correction/Note during generation prep)
I'll remove the `process_next` return type hint to avoid version issues, or just keep it simple. The prompt doesn't specify `process_next`, but it's needed for FIFO processing. I'll keep it.
All good.
Output matches. 
Proceeds. 
[Final Output Generation] -> *Proceeds*

</reasoning_content>

<content>
```python
from collections import deque
from typing import Dict, Optional

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

    def add_job(self, job_id: str, data: dict) -> str:
        self._jobs[job_id] = {"data": data, "status": "pending", "result": None}
        self._queue.append(job_id)
        return job_id

    def get_result(self, job_id: str) -> dict | None:
        job = self._jobs.get(job_id)
        if job and job["status"] == "completed":
            return job["result"]
        return None

    def process_next(self) -> str | None:
        while self._queue:
            job_id = self._queue.popleft()
            if self._jobs[job_id]["status"] == "pending":
                self._jobs[job_id]["status"] = "completed"
                self._jobs[job_id]["result"] = {"status": "completed", "data": self._jobs[job_id]["data"]}
                return job_id
        return None
```
</content>