fix: implement trampoline pattern for GLib callbacks to prevent purego slot exhaustion

[bnema]

Problem

GLib source functions previously allocated a new purego callback slot for every invocation. purego has a hard limit of 2000 slots, so long-running programs that schedule many one-shot idle/timeout callbacks would exhaust the pool and panic.

Solution

The trampoline uses a single purego callback that dispatches through a Go-side map keyed by an opaque ID passed as GLib's user_data pointer. All IdleAdd/TimeoutAdd calls share ONE purego slot regardless of how many are outstanding.

Changes

• Added trampoline infrastructure in templates/glib
• Updated templates/go to use trampoline for IdleAdd/TimeoutAdd family
• Generated code updates in v4/glib/*.go
• Bumped puregotk to Go 1.26 compatible version

Impact

This fixes the issue where dumber would close unexpectedly after running for extended periods due to callback slot exhaustion.

Summary by CodeRabbit

• Chores
  • Updated Go toolchain to 1.26 for build consistency.
  • Bumped an internal dependency to a newer compatible release.
  • Upgraded CI lint tool to a newer version to align linting with current standards.

[coderabbitai]

📝 Walkthrough

Walkthrough

Go toolchain in go.mod is updated from 1.25.3 to 1.26; the replace directive for github.com/jwijenbergh/puregotk is changed from a commit pseudo-version to v0.1.0. CI workflow updates the installed golangci-lint version from v2.6.2 to v2.9.0.

Changes

Cohort / File(s)	Summary
Dependency Management go.mod	Bump go directive from 1.25.3 to 1.26; change replace github.com/jwijenbergh/puregotk from pseudo-version v0.0.0-20260212181341-fb13c245f9f0 to v0.1.0.
CI Workflow .github/workflows/ci.yml	Update golangci-lint installation version from v2.6.2 to v2.9.0.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

Poem

🐇 I hopped through modules, light and spry,

Go 1.26 beneath the sky,
PureGOTK donned a brand-new coat,
Linters tuned to brighter note,
A rabbit's cheer — commit and fly!

🚥 Pre-merge checks | ✅ 3 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Title check	⚠️ Warning	The PR title describes implementing a trampoline pattern for GLib callbacks, but the actual changes shown are only Go toolchain version bumps and golangci-lint updates with no visible implementation of the trampoline pattern itself.	The title claims to implement a significant architectural pattern but the changeset only contains dependency/toolchain updates. Verify if the core implementation changes are missing from this PR, or update the title to accurately reflect that this is a preparatory dependency update.

✅ Passed checks (3 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Merge Conflict Detection	✅ Passed	✅ No merge conflicts detected when merging into main

_{✏️ Tip: You can configure your own custom pre-merge checks in the settings.}

✨ Finishing touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Post copyable unit tests in a comment
• Commit unit tests in branch fix/update-puregotk-go1-26

---

No actionable comments were generated in the recent review. 🎉

---

_{Comment @coderabbitai help to get the list of available commands and usage tips.}