chore: Update closed and opened templates to have compact look

[bbaarriiss]

After we deployed the new notifications, we realized that the amount of emojis are eye-tiring and also the main identifier emojis are not catchy because of the crowded look of many emojis.

Below you will see the before/after comparison.

PR opened (OLD):

PR opened (NEW):

PR Merged (OLD):

PR Merged (NEW):

[claude]

Review

Nice cleanup — the before/after screenshots make the case well, and collapsing the title into the PR link line is the right call. The change is small and low-risk. A few things I found while reading it.

Note: there's no CLAUDE.md in this repo, so I reviewed against .editorconfig and the conventions already established in src/main/resources/templates/en/.

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1. pull_request.opened.template now ends with a dangling blank line (inconsistent with the closed template)

The blank line that used to separate the header from the detail block wasn't removed — it just ended up at the bottom of the file. Byte-level check:

pull_request.opened.template  ->  ... {{pullRequest.title}}\n\n   # trailing blank line
pull_request.closed.template  ->  ... {{pullRequest.title}}\n     # clean

Since Mustache emits the template body verbatim, the opened notification will carry a trailing empty line that the closed one doesn't. Both files are edited in this PR, so it's worth making them match — drop the final newline in pull_request.opened.template:4.

2. This changes user-facing output with no test covering it — and the golden files that look like they cover it are dead

src/test/fixtures/messages/*.txt looks exactly like a set of expected-output golden files, but:

• grep -rn "fixtures" --include=*.kt src/ returns nothing — no Kotlin code reads them.
• Their contents are a third format, older than both the pre- and post-PR templates. pull_request.opened.txt still says **[Eva22/Integrations]** Pull request **Modified MD** was opened by **Eva22**.
• ApplicationTest mocks TemplateHandler outright (every { templateHandler.handleEvent(...) } returns DUMMY_TEMPLATE), so no test ever exercises real rendering.

So the only verification of this change is the manual screenshots in the description. That's acceptable for a two-line template tweak, but the stale fixtures are an active trap — the next person may well assume they're live and that a green build means the output is unchanged.

Worth a follow-up (not a blocker for this PR): a small TemplateHandlerTest that feeds each src/test/fixtures/events/*.json through TemplateHandler.handleEvent and asserts against the matching messages/*.txt, with those files regenerated. That fixture pairing is already sitting there by filename — it just needs wiring up. It would also have caught issue #1 above automatically.

3. {{pullRequest.title}} is HTML-escaped; sibling templates use {{{ }}} for the same field

This is pre-existing (the old 🔖 **Title:** line had it too), but you're touching the line, so it's cheap to fix now. Every other template in the directory uses triple braces for user-supplied titles:

issues.opened.template:1           Issue **{{{issue.title}}}** ...
issues.closed.template:1           Issue **{{{issue.title}}}** ...
issue_comment.created.template:1   on issue **{{{issue.title}}}**

...while both PR templates use {{pullRequest.title}}, which runs through mustache.java's HTML escaper (& -> &, < -> <, etc.).

Flagging with a caveat: whether this is actually visible depends on how Wire renders the message. If it parses markdown into HTML, the entities decode back and you'd never notice; if it renders to native attributed text, a PR titled fix: A & B shows up literally as fix: A & B. I couldn't run it here to confirm which. Easy to check against a real PR title containing & — and if it does render wrong, {{{pullRequest.title}}} both fixes it and matches the rest of the directory.

4. Minor security note: PR titles are untrusted markdown, now rendered adjacent to a link

Anyone who can open a PR on a watched repo controls pullRequest.title, and it's now placed immediately after the PR link on the same line. A title like [click here](https://evil.example) renders as a live link in the Wire notification, and sitting right next to the real PR link it's more plausible as a spoof than it was on its own 🔖 **Title:** line.

To be clear, this is pre-existing and repo-wide, not introduced here — the triple-braced issue titles, comment bodies, and commit messages in the other templates have the same exposure, and note that HTML-escaping doesn't mitigate it either way since [, ], (, ) aren't escaped. Low severity given the trust model (you've presumably already decided to relay repo content into a channel). Not something this PR needs to solve; just worth being aware of if these notifications ever get pointed at public repos.

5. Follow-up: the two notification styles are now further apart

pull_request.opened / pull_request.closed use the emoji-header style; issues.*, push, commit_comment.created, issue_comment.created, and both pull_request_review* templates still use the older **[repo]** ... — style with the em-dash terminator. Entirely fine to defer — but if the compact style is the direction, the rest are a natural next PR so a channel doesn't show two visibly different formats.

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Performance: no impact. DefaultMustacheFactory caches compiled templates internally, and this doesn't change the number or shape of tags.

Verdict: approve modulo #1 (the trailing newline — one-character fix). #2 and #3 are worth a look but shouldn't hold this up.