Human-readable, short, per-board sequential card numbers

[Iameora]

Summary

Please consider adding a short, human-readable, per-board sequential number for cards —
i.e. each board numbers its own cards 1, 2, 3, …, with that number shown next to the card and
usable in the card URL. For context: I'm currently migrating a team from Trello to Planka, and
this is the one gap that's really making itself felt in day-to-day use.

This is separate from the global record ID. The internal Snowflake ID can stay exactly as
it is for storage and API; the request is for an additional, friendly identifier for humans.

The problem (with real examples)

Today a Planka card link looks like this:

http://planka.example/cards/1751693628364817446

That number is a Snowflake-style ID: globally unique, but impossible for a human to read,
remember, dictate, or type. The pain shows up the moment you have to reference a card
outside the board UI:

• Telling a teammate in chat / voice: "the task 1751693628364817446 needs attention" — unusable.
• Pasting a list of tasks to work on into Slack/email/a meeting note.
• Writing a commit message or a doc that points at a specific card.
• Reading a card number out loud in a standup.

As a familiar reference point, a comparable card URL elsewhere looks like:

.../c/Casddwwe/755-improve-scheduling

The 755 is trivial for a human to hold in their head and say "task 755 needs work". That
one small number is what makes cross-tool, cross-conversation references practical — and it's
exactly the affordance I lose when moving boards over to Planka.

What's being requested

1. Each board maintains its own counter, starting at 1 and incrementing per card created
   on that board (board A and board B both have a card #1).
2. The number is shown in the UI, e.g. a small #42 near the card title (and visible on the
   card itself in the list).
3. The number is usable to reference / open the card — ideally included in the card URL
   (/c/<shortcode>/<number>-<slug>), so links are both stable and readable.
4. The number is stable once assigned (deleting a card does not renumber the others).
5. Search / filter by that number (e.g. type #42 to jump to the card) would be a great bonus.

Why per-board (and not global)

Per-board numbering keeps the numbers small and meaningful in context — board "Backlog"
card 12 is just "12" to the people working that board, regardless of how many thousands of
cards exist system-wide. A global counter would quickly grow into large, less memorable numbers
and defeat the purpose. Scoping the counter per board keeps it human-friendly.

Relation to existing threads

• Issue Open ideas of enhancements #361 ("Open ideas of enhancements") already lists this as one sub-point
  ("Add task numbering in each board so each task has its id: 1, 2, 3…"), but it's buried
  inside a grab-bag of unrelated ideas, so it's hard to track or vote on specifically. This
  discussion is meant to isolate just that request.
• Discussion Customizable Card ID Prefixes #1462 ("Customizable Card ID Prefixes") asks for configurable prefixes like
  #PRJ01-xxxx. That's complementary but different: a prefix is cosmetic styling on top
  of an identifier — it doesn't, by itself, give you the short sequential number. The two
  features compose nicely (prefix + per-board number → PRJ-42), but the core need here is
  the short per-board number itself.

Why it matters

Speaking from an in-progress Trello migration, this is the single thing that keeps making
itself felt. Everything else in Planka has been a pleasure, but without a memorable card number
the cards can't be referenced naturally in the places where work is actually coordinated — chat,
calls, docs, commits. A simple incremental per-board number would close that gap and make the
switch frictionless.

Thanks for the great project! 🙏