chore: bump dev toolchain (go 1.26.5, node 26) and add zed/gopls config

[TerrorSquad]

Summary

Updates the dev toolchain in mise.toml to the latest and adds the Zed + gopls-via-mise config.

Tool	Was	Now
go	1.23.8	1.26.5
node	24	26
pnpm	11	11 (latest 11.x)

CI impact

Every workflow extracts its version from mise.toml (grep '^go = ' / '^node = ' / '^pnpm = '), so the bump propagates automatically — no workflow edits needed. Confirmed the greps resolve to 1.26.5 / 26 / 11 with no collision from the go:...gopls line.

Verification

• go build ./... + go test ./... pass on go 1.26.5
• pnpm install --frozen-lockfile + vitepress build pass on node 26.5.0 / pnpm 11.13.1 (lockfile unchanged)

Notes

• go.mod's go 1.23.0 directive left as-is — it's the compatibility floor for go install, intentionally separate from the dev toolchain pin.

🤖 Generated with Claude Code

[TerrorSquad]

Self-review — config-only change, verified locally:

• mise.toml grep extraction resolves to go 1.26.5 / node 26 / pnpm 11; the go:...gopls line starts with a quote so ^go = doesn't match it (no collision).
• go build + full test suite pass on 1.26.5; VitePress builds on node 26.5.0 / pnpm 11.13.1 with the lockfile unchanged.
• go.mod floor intentionally left at go 1.23.0.

The one thing only CI can confirm is that actions/setup-go@v6 has 1.26.5 in its version manifest (local install came from mise, not setup-go). The Build & Vet check will prove it — merging once it's green.