chore(ci): upgrade Go 1.25 to 1.26

Bump Go version across go.mod, CI workflows, and docs to leverage
Go 1.26 improvements (Green Tea GC, faster cgo, new stdlib packages).

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: AnnatarHe

.github/workflows/pr-check.yaml

@@ -25,7 +25,7 @@ jobs:
       - name: Setup Go
         uses: actions/setup-go@v5
         with:
-          go-version: "1.25"
+          go-version: "1.26"
 
       - name: Cache Go modules
         uses: actions/cache@v4

.github/workflows/release.yaml

@@ -26,7 +26,7 @@ jobs:
       - run: git fetch --force --tags
       - uses: actions/setup-go@v5
         with:
-          go-version: "1.25"
+          go-version: "1.26"
       - uses: PromptPal/github-action@v1.0.3
         env:
           PROMPTPAL_ENDPOINT: ${{ secrets.PROMPTPAL_ENDPOINT }}

CLAUDE.md

@@ -10,7 +10,7 @@ ShellTime CLI is a Go-based command-line tool for tracking DevOps work. It consi
 
 ## Development Commands
 
-**Requires Go 1.25+**
+**Requires Go 1.26+**
 
 ### Building
 ```bash

go.mod

@@ -1,6 +1,6 @@
 module github.com/malamtime/cli
 
-go 1.25
+go 1.26
 
 require (
 	github.com/ThreeDotsLabs/watermill v1.5.1