Add packaging infrastructure for v1.3.0

New helpers for npm, Linux, and Homebrew packaging:

- With.Packaging.npm(): Assembles Scala.js output into npm packages
  with npmPrepare (pure sbt) and npmPack tasks. Supports template
  mode and TypeScript definition auto-discovery.

- With.Publishing.npm(): Publishes npm packages to npmjs.com and/or
  GitHub Packages with NPM_TOKEN/GITHUB_TOKEN auth.

- With.Packaging.linux(): Creates tar.gz archives of Scala Native
  binaries with auto-detected OS/arch and optional overrides.

- With.Packaging.homebrew(): Generates Homebrew formula .rb files
  for JVM universal or Scala Native variants with SHA256 hashing.

- With.Packaging.windowsMsi(): Placeholder for future implementation.

Includes 3 new scripted tests (20 total, all passing) and full
README documentation with migration notes.

Integration-tested in riddl project for npm packaging/publishing
of riddl-lib to npmjs.com.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: respencer-ncl

CLAUDE.md

@@ -14,7 +14,7 @@ SBT plugin providing build infrastructure and configuration helpers for Ossum
 Inc. projects. Defines declarative project types and configuration options
 used across all Scala projects in the organization.
 
-**Current version: 1.2.5** (released Jan 2026)
+**Current version: 1.3.0** (released Feb 2026)
 
 ## Project Types Provided
 
@@ -98,10 +98,37 @@ provided transitively. Only use `With.Akka.forRelease()` if you need modules
 beyond what the server infrastructure provides (e.g., Kafka, Insights,
 Management, Projections).
 
+**`With.Packaging.npm(...)`** - npm package assembly (v1.3.0+)
+- For Scala.js projects, assembles output into npm-publishable package
+- Signature: `(scope, pkgName, pkgDescription, keywords, esModule,
+  templateFile)(project)`
+- Tasks: `npmPrepare` (pure sbt), `npmPack` (requires npm on PATH)
+- Template mode: set `templateFile` with `VERSION_PLACEHOLDER`
+- TypeScript defs auto-discovered from `<module>/types/index.d.ts`
+
+**`With.Publishing.npm(...)`** - npm registry publishing (v1.3.0+)
+- Signature: `(registries)(project)` where registries is
+  `Seq("npmjs")` and/or `Seq("github")`
+- Auth via `NPM_TOKEN` / `GITHUB_TOKEN` env vars
+
+**`With.Packaging.homebrew(...)`** - Homebrew formula generation (v1.3.0+)
+- Signature: `(formulaName, binaryName, pkgDescription, homepage,
+  javaVersion, tapRepo, variant)(project)`
+- Variants: `"universal"` (JVM with openjdk dep) or `"native"`
+- Task: `homebrewGenerate` produces `.rb` file with SHA256
+
+**`With.Packaging.linux(...)`** - Native binary tar.gz archive (v1.3.0+)
+- Signature: `(pkgName, pkgDescription, arch, os, includeReadme,
+  includeLicense)(project)`
+- Auto-detects host OS/arch (Scala Native compiles for host only)
+- Task: `linuxPackage` produces `<name>-<ver>-<os>-<arch>.tar.gz`
+
 **Other parameterized options:**
 - `With.Laminar(...)` - Laminar + DOM dependencies
 - `With.MiMa(...)` - Binary compatibility checking
 - `With.Packaging.universal(...)` - Universal packaging
+- `With.Packaging.dockerDual(...)` - Dev/prod Docker images
+- `With.Packaging.windowsMsi(...)` - Placeholder (not yet implemented)
 - `With.GithubPublishing` - GitHub Packages publishing
 
 **For all configuration options, examples, and migration notes, refer to
@@ -135,7 +162,7 @@ sbt scalafmt
 All Scala projects in ossuminc use this plugin. Add to `project/plugins.sbt`:
 
 ```scala
-addSbtPlugin("com.ossuminc" % "sbt-ossuminc" % "1.2.5")
+addSbtPlugin("com.ossuminc" % "sbt-ossuminc" % "1.3.0")
 ```
 
 ### Example CrossModule Definition

NOTEBOOK.md

@@ -2,11 +2,78 @@
 
 ## Current Status
 
-**Version 1.2.5 released.** Fixed CI scripted tests and AKKA_REPO_TOKEN
-propagation. All 16 scripted tests now pass in CI.
-
-**Active branch: feature/docker-dual** - Adding dual Docker image support
-(dev/prod) for RIDDL services deployment to GKE.
+**Version 1.3.0 released** (Feb 2026). Packaging infrastructure complete.
+
+Previous release: v1.2.5 (Jan 2026).
+
+### Resolved Design Questions
+
+1. **Scala.js optimization task**: Use `fullOptJS` (applies Google Closure
+   Compiler optimization). NOT `fullLinkJS` — the plan's original
+   recommendation was incorrect; `fullOptJS` is not deprecated and produces
+   the optimized output needed for npm packaging.
+
+2. **Homebrew formula variants**: Support both JVM universal and Native
+   binary variants via a `variant` parameter (`"universal"` or `"native"`).
+
+3. **Linux tar.gz architecture**: Auto-detect host OS and architecture as
+   default (since Scala Native can only compile for the host platform),
+   with optional `arch` and `os` parameter overrides. Multi-arch
+   distribution requires CI matrix runners for each target platform.
+
+### Implementation Phases
+
+| Phase | Feature | Status |
+|-------|---------|--------|
+| 1 | NpmPackaging (`npmPrepare`, `npmPack`) | ✅ DONE |
+| 2 | NpmPublishing (`npmPublish*` tasks) | ✅ DONE |
+| 3 | Linux tar.gz packaging | ✅ DONE |
+| 4 | Homebrew formula generation | ✅ DONE |
+| 5 | Windows MSI placeholder | ✅ DONE |
+| 6 | Documentation & Release (tag 1.3.0) | ✅ DONE |
+
+### Session Feb 3, 2026 — v1.3.0 Released
+
+All 6 phases of the packaging plan implemented and released.
+Integration-tested in riddl project (npm packaging/publishing to
+npmjs.com for ossum.ai site consumption).
+
+**New files created:**
+- `NpmPackaging.scala` — Keys, `npm()` method, `npmPrepare`/`npmPack`
+  tasks, template mode with `VERSION_PLACEHOLDER`, TypeScript defs
+  convention (`js/types/index.d.ts`), JSON generation via string builder
+- `NpmPublishing.scala` — `npmPublish`, `npmPublishNpmjs`,
+  `npmPublishGithub` tasks, auth via env vars (`NPM_TOKEN`,
+  `GITHUB_TOKEN`), extracted helper methods to avoid sbt `.value` macro
+  restrictions inside lambdas
+- `HomebrewPackaging.scala` — `homebrewGenerate` task, supports
+  `"universal"` (JVM with openjdk dep) and `"native"` (Scala Native)
+  variants, SHA256 from local artifact, Ruby class name generation,
+  uses `Def.task` variant selection at build-definition time to avoid
+  sbt macro restrictions
+
+**Modified files:**
+- `Packaging.scala` — Added delegation methods `npm()`, `homebrew()`,
+  `linux()`, `windowsMsi()` (placeholder); added `linuxPackage`,
+  `linuxPackageArch`, `linuxPackageOs` keys; added `detectArch`,
+  `detectOs` private helpers; imported Scala Native `nativeLink`
+- `Publishing.scala` — Added `npm()` delegation method
+
+**New scripted tests (20 total now):**
+- `npm-packaging` — Verifies `npmPrepare` produces `package.json`,
+  `main.js`, `README.md` with correct content assertions
+- `linux-packaging` — Verifies config settings (doesn't link; consistent
+  with existing `native` test pattern)
+- `homebrew` — Runs `homebrewGenerate` on a `Program`, verifies formula
+  contains class name, description, homepage, JDK dep, license, SHA256
+
+**Technical lessons learned:**
+- sbt `.value` is a macro — ALL `.value` calls in a task body are
+  resolved regardless of runtime control flow (match/if/foreach). Must
+  either extract to helper methods (NpmPublishing) or use `Def.task`
+  variant selection at build-definition time (HomebrewPackaging).
+- `fullOptJS` is NOT deprecated; it applies Google Closure Compiler
+  optimization needed for production npm packages.
 
 ## Work Completed (Recent)
 
@@ -268,28 +335,32 @@ Run scripted tests on every PR. Skip Akka test in CI (requires credentials).
 
 ## Test Coverage Status
 
-### Current Test Results (Jan 29, 2026)
-
-| Test Scenario  | Purpose                       | Status                    |
-|----------------|-------------------------------|---------------------------|
-| akka           | Akka dependencies             | ✅ PASS                   |
-| asciidoc       | AsciiDoc document generation  | ✅ PASS                   |
-| basic          | Basic module configuration    | ✅ PASS                   |
-| cross          | Cross-platform (JVM/JS/Native)| ✅ PASS                   |
-| everything     | Full feature set              | ✅ PASS                   |
-| idea-plugin    | IntelliJ plugin development   | ✅ PASS                   |
-| laminar        | Laminar UI dependencies       | ✅ PASS                   |
-| mima           | Binary compatibility checking | ✅ PASS                   |
-| multi          | Multi-module projects         | ✅ PASS                   |
-| native         | Scala Native compilation      | ✅ PASS                   |
-| packaging      | Universal packaging           | ✅ PASS                   |
-| program        | Executable programs           | ✅ PASS                   |
-| publishing     | Publishing helper (new)       | ✅ PASS                   |
-| scalably-typed | TypeScript facades            | ✅ PASS                   |
-| scalajs        | Scala.js compilation          | ✅ PASS                   |
-| scalatest      | Scalatest helper (new)        | ✅ PASS                   |
-
-**Pass rate:** 16/16 (100%)
+### Current Test Results (Feb 3, 2026)
+
+| Test Scenario    | Purpose                        | Status   |
+|------------------|--------------------------------|----------|
+| akka             | Akka dependencies              | ✅ PASS  |
+| asciidoc         | AsciiDoc document generation   | ✅ PASS  |
+| basic            | Basic module configuration     | ✅ PASS  |
+| cross            | Cross-platform (JVM/JS/Native) | ✅ PASS  |
+| docker-dual      | Dev/prod Docker images         | ✅ PASS  |
+| everything       | Full feature set               | ✅ PASS  |
+| homebrew         | Homebrew formula generation    | ✅ PASS  |
+| idea-plugin      | IntelliJ plugin development    | ✅ PASS  |
+| laminar          | Laminar UI dependencies        | ✅ PASS  |
+| linux-packaging  | Native binary tar.gz archive   | ✅ PASS  |
+| mima             | Binary compatibility checking  | ✅ PASS  |
+| multi            | Multi-module projects          | ✅ PASS  |
+| native           | Scala Native compilation       | ✅ PASS  |
+| npm-packaging    | npm package assembly           | ✅ PASS  |
+| packaging        | Universal packaging            | ✅ PASS  |
+| program          | Executable programs            | ✅ PASS  |
+| publishing       | Publishing helper              | ✅ PASS  |
+| scalably-typed   | TypeScript facades             | ✅ PASS  |
+| scalajs          | Scala.js compilation           | ✅ PASS  |
+| scalatest        | Scalatest helper               | ✅ PASS  |
+
+**Pass rate:** 20/20 (100%)
 
 ### Missing Test Coverage
 
@@ -351,6 +422,11 @@ Create `examples/` with working `build.sbt` files:
 
 | Decision | Rationale | Date |
 |----------|-----------|------|
+| Delegation pattern for new helpers | Keeps API at `With.Packaging.npm()` not `With.NpmPackaging` | 2026-02-03 |
+| `fullOptJS` for npm packaging | Closure Compiler optimization needed; not deprecated | 2026-02-03 |
+| `Def.task` for variant selection | sbt `.value` macro resolves all refs in task body | 2026-02-03 |
+| Auto-detect OS/arch for linux() | Scala Native compiles for host only; CI matrix for multi-arch | 2026-02-03 |
+| No JSON library for package.json | Avoids dependency; string builder sufficient for Scala 2.12 | 2026-02-03 |
 | Switch Sonatype → GitHub Packages | Simpler auth for ossuminc org | 2026-01-15 |
 | Use symlink approach | Consistent with project/ pattern | 2026-01-15 |
 | Rename With.Javascript → With.ScalaJS | Clearer naming | 2026-01-15 |