Text box formatter: draw each sentence in an ASCII box

Implement format_boxes(sentences: list[str]) -> list[str].

Each sentence is a non-empty string of printable ASCII characters and spaces. Draw every sentence in its own ASCII box and return the drawing as a list of lines.

Rules:

• All boxes have the same inner width: the length of the longest sentence.
• A border line is +, then width + 2 dashes, then +.
• A text row is | , the sentence left-aligned, spaces up to width, then |.
• Boxes are stacked top to bottom in input order. Neighbouring boxes share one border line, so n sentences produce 2n + 1 lines.
• Copy each sentence exactly, including any inner spaces.

Example

sentences = ["Hi there", "A longer one", "Ok"]

+--------------+
| Hi there     |
+--------------+
| A longer one |
+--------------+
| Ok           |
+--------------+

Part 2. Add format_wrapped_boxes(sentences, max_width, mode). The inner width is now min(longest sentence, max_width). Wrap each sentence greedily onto as many rows of its box as needed, with one space between words; cut a word longer than the width into width-sized pieces. Align each row by mode: left, right, center, or justify (spread spaces evenly, extra spaces go to the leftmost gaps, and the last row of each sentence stays left-aligned).

sentences = ["the quick brown fox jumps", "hello"], max_width = 10, mode = "justify"

+------------+
| the  quick |
| brown  fox |
| jumps      |
+------------+
| hello      |
+------------+

Constraints: up to 10^4 sentences, each up to 10^3 characters; max_width >= 1.

Clarifying questions

• Is the output a list of strings without trailing newlines?
• What should an empty list of sentences return: an empty list, or one border line?
• Should leading or trailing spaces in a sentence be kept as part of its width?
• In Part 2, is the inner width min(longest sentence, max_width) even when wrapping would allow a narrower box?

What a strong answer covers

• Computes the width once, builds one border string, and emits border, row, border, row, ..., border: 2n + 1 lines in O(total characters).
• Pads with ljust or explicit spaces so every row has the same length.
• Part 2: wraps each sentence greedily, splits words longer than the width into width-sized pieces, then aligns each row; justify spreads the gaps evenly, gives extra spaces to the leftmost gaps, and leaves a sentence's last row and any one-word row left-aligned.
• Tests the examples, a single sentence, a sentence exactly max_width long, a very long word, and every alignment mode.

Follow-ups

• Give each box its own width.
• Lay the boxes out side by side in columns.
• Support Unicode text where characters have different display widths.