feat: room abbreviations with hover tooltips and space inheritance

[Just-Insane]

Description

Adds a room abbreviations feature: moderators can define term/definition pairs in room settings. Defined terms are highlighted with a dotted underline in messages and show a tooltip on hover (tap-to-pin on mobile). Abbreviations defined in a parent space are inherited by child rooms and nested spaces, with overrides allowed at each level. The settings UI shows a flat list of inherited and locally-defined entries.

Fixes #

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings

AI disclosure:

• Partially AI assisted (clarify which code was AI assisted and briefly explain what it does).
• Fully AI generated (explain what all the generated code does in moderate detail).

The code adds changes that allow for setting and viewing room abbreviations, with an on-hover tooltip (or press on mobile - semi-persistent). It stores these in the room state under a new key, and recursively fetches abbreviations from the space level. This also adds regex so that abbreviations correctly work at word boundaries. Also adds the needed hooks to room.ts and slidingSync.ts

[dozro]

requested review from @Rosy-iso because it seems to be an ui change and from @TastelessVoid because they (according to github) recently worked on the changed files

[Rosy-iso]

I'll give it a look soon

[Rosy-iso]

Interesting feature! I like the concept a lot actually, is this idea from you or is it from some matrix spec?

That aside, consistency wise things are mostly okay: the abbreviations list is perfectly consistent while the abbreviation creation modal is...almost consistent. While the fact that the modal itself is not split into multiple sections might seem the issue at first, that is actually perfectly fine as this is something with precedence that is rarely done for the few settings that must work with multiple elements at once (room settings, emoji pack settings)

The inaccuracy is in the spacing and placement: the elements of the modal are too close together and the button should be on the left, not the right, use the other modals as reference

[Just-Insane]

The abbreviation concept is mine, I wanted a lightweight way for rooms to define their own jargon/acronyms without needing a full wiki or pinned message. Saw a few people asking about PMP messages were while that was being developed.

Fixed both spacing issues: bumped the form's internal gap from 200 to 400 (matching the pattern in e.g. the room profile form), and removed justifyContent="End" from the button row so it sits on the left like the other modals.

[Just-Insane]

Seems to be an issue with abbreviations not showing properly, trying to track that down.

Edit: looks good now, looks like it was an issue with messages sent via PMPs

[Rosy-iso]

Seems to be consistent now indeed, this works :)

(This approval is purely UI wise, the code should still be audited and reviewed separately by someone else!)