Closes [issue #50](#50)
## Summary
Refactors the Dockerfile to use a separate lint stage with a pinned golangci-lint Docker image, following the pattern used by [sneak/pixa](https://git.eeqj.de/sneak/pixa). This replaces the previous approach of installing golangci-lint via curl in the builder stage.
## Changes
### Dockerfile
- **New `lint` stage** using `golangci/golangci-lint:v2.11.3` (Debian-based, pinned by sha256 digest) as a separate build stage
- **Builder stage** depends on lint via `COPY --from=lint /src/go.sum /dev/null` — build won't proceed unless linting passes
- **Go bumped** from 1.24 to 1.26.1 (`golang:1.26.1-bookworm`, pinned by sha256)
- **golangci-lint bumped** from v1.64.8 to v2.11.3
- All three Docker images (golangci-lint, golang, alpine) pinned by sha256 digest
- Debian-based golangci-lint image used (not Alpine) because mattn/go-sqlite3 CGO does not compile on musl (off64_t)
### Linter Config (.golangci.yml)
- Migrated from v1 to v2 format (`version: "2"` added)
- Removed linters no longer available in v2: `gofmt` (handled by `make fmt-check`), `gosimple` (merged into `staticcheck`), `typecheck` (always-on in v2)
- Same set of linters enabled — no rules weakened
### Code Fixes (all lint issues from v2 upgrade)
- Added package comments to all packages
- Added doc comments to all exported types, functions, and methods
- Fixed unchecked errors flagged by `errcheck` (sqlDB.Close, os.Setenv in tests, resp.Body.Close, fmt.Fprint)
- Fixed unused parameters flagged by `revive` (renamed to `_`)
- Fixed `gosec` G120 warnings: added `http.MaxBytesReader` before `r.ParseForm()` calls
- Fixed `staticcheck` QF1012: replaced `WriteString(fmt.Sprintf(...))` with `fmt.Fprintf`
- Fixed `staticcheck` QF1003: converted if/else chain to tagged switch
- Renamed `DeliveryTask` → `Task` to avoid package stutter (`delivery.Task` instead of `delivery.DeliveryTask`)
- Renamed shadowed builtin `max` parameter to `upperBound` in `cryptoRandInt`
- Used `t.Setenv` instead of `os.Setenv` in tests (auto-restores)
### README.md
- Updated version requirements: Go 1.26+, golangci-lint v2.11+
- Updated Dockerfile description in project structure
## Verification
`docker build .` passes cleanly — formatting check, linting, all tests, and build all succeed.
Co-authored-by: clawbot <clawbot@noreply.git.eeqj.de>
Reviewed-on: #55
Co-authored-by: clawbot <clawbot@noreply.example.org>
Co-committed-by: clawbot <clawbot@noreply.example.org>
The top-level entity that groups entrypoints and targets is now called
Webhook (was Processor). The inbound URL endpoint entity is now called
Entrypoint (was Webhook). This rename affects database models, handler
comments, routes, and README documentation.
closes #12
