<reasoning_content>
*   Goal: Implement a basic job queue in Python.
    *   Class Name: `JobQueue`.
    *   Methods:
        *   `add_job(job_id: str, data: dict) -> str`
        *   `get_result(job_id: str) -> dict | None`
    *   Ordering: FIFO (First-In-First-Out).
    *   Storage: Store jobs until processed.
    *   Unique ID: Return `job_id` when added.
    *   Mechanism: Since the prompt asks for a "job queue" but doesn't explicitly ask for a worker thread/process, I should provide a structure where jobs can be "processed" (represented by a status/result).
    *   *Self-Correction:* In a standard coding interview scenario for a "Job Queue", usually there's a `process_jobs` method or a background worker. However, the prompt specifically lists only two methods: `add_job` and `get_result`.
    *   *Interpretation:*
        *   `add_job`: Put the job in a queue.
        *   `get_result`: Check if the job is done and return the result.
        *   Wait, if there's no `process` method, how do they finish?
        *   Maybe the prompt implies that jobs are processed internally? Or perhaps I should include a simple `process_next_job` or similar to make it functional?
        *   Actually, looking at the example: `queue.add_job(...)` then `result = queue.get_result(...)`.
        *   Since the prompt says "Jobs should be processed in FIFO", but doesn't provide a `process` method in the requirements list, I should probably implement a way for them to be processed or assume a mock processing logic.
        *   Let's look at the requirements again. "The queue should store jobs internally until they are processed". This implies a state change from "pending" to "completed".
        *   To make it runnable and useful, I'll add a private method or a way to "process" them, but keep the public API strictly to the requirements.
        *   Actually, if I only have `add_job` and `get_result`, the "processing" must happen somewhere. I'll implement a `process_jobs` method or similar, but wait, the prompt says "Write only the Python code" and "Create a `JobQueue` class with the following methods: [list]".
        *   Maybe the "processing" is simulated?
        *   Let's assume the user wants a structure where jobs are added to a queue, and I'll provide a simple way to "complete" them so `get_result` works.

    *   Actually, I'll just implement the two requested methods. To handle the "FIFO" and "processed" requirement, I'll use a `collections.deque` for the queue and a dictionary to store results.
    *   *Wait*, if I don't have a `process` method, how does a job move from "queued" to "completed"?
    *   I will add a `process_jobs` method internally or just a way to mock it.
    *   Let's re-read: "Jobs should be processed in FIFO order".
    *   Okay, I'll add a simple `process_next()` method just to make the class actually functional, even if not strictly in the list, or I'll assume the user wants a way to simulate processing.
    *   Actually, I'll stick strictly to the requested methods. If a job is added, it's in the queue. I'll add a `complete_job` helper or just assume that `get_result` will return `None` until some logic finishes it.
    *   Let's look at the prompt again: "Write only the Python code".

    Revised plan:
    1. Use `collections.deque` for the queue (FIFO).
    2. Use a dictionary to store `results`.
    3. Since the prompt doesn't provide a `process` method in the requirement list but says "Jobs should be processed", I'll add a `process_next()` method. It's the only way to satisfy the "processed" logic.
    4. Oh, looking at the example: `job_id = queue.add_job(...)`, then `result = queue.get_result(...)`.
    5. Maybe I should simulate the processing inside `add_job`? No, that's not a queue.
    6. I'll implement the two required methods + a `process_next` method to actually move things through the queue.

    Actually, I'll just implement the two requested methods. If I add more, I might violate the prompt. If I don't add a processing mechanism, `get_result` will always be `None`.
    Wait, I'll just implement the two methods and a simple internal "processing" logic or just provide a `complete_job` method to allow the example to work.

    Let's try this:
    `add_job`: puts into `self._queue` and `self._results` (status 'pending').
    `get_result`: returns from `self._results`.
    To make it "processed", I'll add a `process_jobs` method.

    *Decision*: I will include a `process_jobs` method even if not explicitly in the bullet points, because "Jobs should be processed" is a requirement. Or, I can make `add_job` trigger a processing simulation. No, a queue implies a consumer.

    Let's provide a clean implementation using `deque` and a dictionary. I'll add a `process_next_job` method to satisfy the "processed" requirement.

    Wait, I'll check the requirements again.
    1. `add_job`
    2. `get_result`
    3. FIFO order
    4. Store until processed
    5. Unique ID

    I'll implement `process_next_job` as well because otherwise the code is useless.

    *Actually*, I'll just implement the two methods and a simple logic where `add_job` puts it in a list, and I'll add a simple `complete_job` method or similar.

    Let's look at common patterns. A JobQueue usually has a worker. Since I can't write a full multi-threaded worker in a "basic" request without more instructions, I'll just implement a method that mimics processing.

    Actually, I'll just stick to the 2 methods and provide a `process_all` or `process_next` method to satisfy the FIFO logic.

    ```python
    from collections import deque
    from typing import Dict, 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))
            self.results[job_id] = None # Initially no result
            return job_id

        def process_next_job(self):
            # Helper to actually "process" a job so get_result works
            if self.queue:
                job_id, data = self.queue.popleft()
                # Simulate processing
                self.results[job_id] = {"status": "completed", "data": data}

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

    Wait, if I include `process_next_job` it's not in the requirements.
    Maybe I should just implement the two methods and the "processing" happens automatically or is assumed?

    Let's try a different approach. The requirement "Jobs should be processed in FIFO order" implies that there is a mechanism for processing. I'll include a `process_jobs` method.

    Actually, I'll just write the two methods and a simple `process_next` to satisfy the logic.

    Wait, the prompt says "Write only the Python code". I'll provide the class with the two methods and an internal processing method.

    Actually, let's keep it simple. I will add a `process_next` method because "Jobs should be processed" is a requirement.

    Revised Code structure:
    - `self._queue` (deque)
    - `self._results` (dict)
    - `add_job`
    - `get_result`
    - `process_jobs` (to fulfill the "should be processed" requirement).

    Wait, I can make `add_job` auto-process if I want it to be simple? No, that's not a queue.

    Let's just provide the two methods and a simple `process_next_job` method.

    Actually, looking at the example:
    `job_id = queue.add_job(...)`
    `result = queue.get_result(...)`
    The comment says `# After processing...`. This implies something happened between the two lines. This means the queue must have a way to be processed.

    Final implementation plan:
    - `add_job` adds to deque.
    - `get_result` looks up in a dict.
    - I will add `process_next_job` to fulfill the "processed" requirement.

    Wait, the prompt says "Create a JobQueue class with the following methods: [2 items]".
    If I add a 3rd, I might fail a strict check.
    If I don't add a 3rd, the code is technically incomplete because jobs never get "processed".
    I'll add a method called `process_jobs`.

    One more thought: What if the "processing" is supposed to be thread-based?
    If I use a `threading.Thread`, I can have a background worker. That makes the most sense for a "Job Queue".

    Let's try the Threading approach.
    - `add_job` adds to a `queue.Queue`.
    - A background thread pulls from the queue and puts results in a dict.
    - `get_result` checks the dict.

    This satisfies:
    1. `add_job` and `get_result` methods exist.
    2. FIFO (Queue handles this).
    3. Store until processed.
    4. Unique ID.
    5. "Jobs should be processed" (happens in background).

    This is the most professional implementation of a "Job Queue".

    Wait, "Basic". Threading might be too much.
    Let's stick to a simple list/deque and a `process_next` method.

    Actually, I'll just write exactly what is asked for and a simple way to process.

    Wait, I'll just write the two methods and a `process_next_job` method.

    Let's refine:
    ```python
    from collections import deque
    from typing import Dict, 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))
            self._results[job_id] = None
            return job_id

        def process_next_job(self):
            if self._queue:
                job_id, data = self._queue.popleft()
                # Simulate work
                self._results[job_id] = {"status": "success", "data": data}

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

    Actually, I will just provide the two requested methods and a `process_next_job` method to make the example runnable.

    Wait, one more look at the prompt. "Write only the Python code, no explanations."
    I will provide a clean, concise class.

    Actually, I'll use a thread to make it a "real" job queue as it's the most standard interpretation of "Job Queue".

    No, "Basic" usually implies no threading unless asked.

    Let's go with the simple manual processing.
</reasoning_content>

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

class JobQueue:
    def __init__(self):
        # FIFO queue to store jobs as (job_id, data)
        self._queue: deque = deque()
        # Dictionary to store results keyed by job_id
        self._results: Dict[str, dict | None] = {}

    def add_job(self, job_id: str, data: dict) -> str:
        """Add a job to the queue and return its unique ID."""
        self._queue.append((job_id, data))
        self._results[job_id] = None
        return job_id

    def process_next_job(self) -> None:
        """
        Helper method to process the next job in the FIFO queue.
         While not explicitly listed in the requirements, it is 
         necessary to fulfill the "jobs should be processed" 
         requirement so that get_result returns a value.
        """
        if self._queue:
            job_id, data = self._queue.popleft()
            # Simulate processing logic
            self._results[job_id] = {"status": "completed", "result": data}

    def get_result(self, job_id: str) -> dict | None:
        """Get the result of a completed job by its ID."""
        return self._results.get(job_id)

# Example usage:
if __name__ == "__main__":
    queue = JobQueue()
    job_id = queue.add_job("job1", {"task": "process_data"})
    
    # Simulate the processing step
    queue.process_next_job()
    
    result = queue.get_result("job1")
    print(result)
```
</content>