Vendor pinned prettier/format toolchain from prompts scaffold (closes #203)

Replace the unpinned `npx prettier --tab-width 4` in `script/fmt` with the
canonical toolchain vendored from `sneak/prompts`: `.prettierrc` (tabWidth 4,
proseWrap always), pinned `package.json` + `yarn.lock` (prettier 3.8.1), and a
`.prettierignore` that unions the scaffold entries with the repo's `*.min.js`
line. `script/bootstrap` now installs a pinned node/yarn via a hash-verified
nvm release archive (never curl-pipe-sh), so prettier stops being an unpinned
host tool. `script/fmt` runs the pinned prettier via `.prettierrc` over
`static/js/*.js` and `**/*.md`, keeping gofmt/goimports. All existing markdown
is reflowed to house style; `static/js/alpine.min.js` stays byte-identical.

Model: opus-4-8

CONVENTIONS.md

@@ -1,6 +1,8 @@
 # Go HTTP Server Conventions
 
-This document defines the architectural patterns, design decisions, and conventions for building Go HTTP servers. All new projects must follow these standards.
+This document defines the architectural patterns, design decisions, and
+conventions for building Go HTTP servers. All new projects must follow these
+standards.
 
 ## Table of Contents
 
@@ -25,18 +27,18 @@ This document defines the architectural patterns, design decisions, and conventi
 
 These libraries are **mandatory** for all new projects:
 
-| Purpose | Library | Import Path |
-|---------|---------|-------------|
-| Dependency Injection | Uber fx | `go.uber.org/fx` |
-| HTTP Router | go-chi | `github.com/go-chi/chi` |
-| Logging | slog (stdlib) | `log/slog` |
-| Configuration | Viper | `github.com/spf13/viper` |
-| Environment Loading | godotenv | `github.com/joho/godotenv/autoload` |
-| CORS | go-chi/cors | `github.com/go-chi/cors` |
-| Error Reporting | Sentry | `github.com/getsentry/sentry-go` |
-| Metrics | Prometheus | `github.com/prometheus/client_golang` |
-| Metrics Middleware | go-http-metrics | `github.com/slok/go-http-metrics` |
-| Basic Auth | basicauth-go | `github.com/99designs/basicauth-go` |
+| Purpose              | Library         | Import Path                           |
+| -------------------- | --------------- | ------------------------------------- |
+| Dependency Injection | Uber fx         | `go.uber.org/fx`                      |
+| HTTP Router          | go-chi          | `github.com/go-chi/chi`               |
+| Logging              | slog (stdlib)   | `log/slog`                            |
+| Configuration        | Viper           | `github.com/spf13/viper`              |
+| Environment Loading  | godotenv        | `github.com/joho/godotenv/autoload`   |
+| CORS                 | go-chi/cors     | `github.com/go-chi/cors`              |
+| Error Reporting      | Sentry          | `github.com/getsentry/sentry-go`      |
+| Metrics              | Prometheus      | `github.com/prometheus/client_golang` |
+| Metrics Middleware   | go-http-metrics | `github.com/slok/go-http-metrics`     |
+| Basic Auth           | basicauth-go    | `github.com/99designs/basicauth-go`   |
 
 ---
 
@@ -85,7 +87,8 @@ project-root/
 ### Key Principles
 
 - **`cmd/{appname}/`**: Only the entry point. Minimal logic, just bootstrapping.
-- **`internal/`**: All application packages. Not importable by external projects.
+- **`internal/`**: All application packages. Not importable by external
+  projects.
 - **One package per concern**: config, database, handlers, middleware, etc.
 - **Flat handler files**: One file per handler or logical group of handlers.
 
@@ -190,7 +193,8 @@ Providers are resolved automatically by fx, but conceptually follow this order:
 2. `logger.New` - Logger (depends on Globals)
 3. `config.New` - Configuration (depends on Globals, Logger)
 4. `database.New` - Database (depends on Logger, Config)
-5. `healthcheck.New` - Health check (depends on Globals, Config, Logger, Database)
+5. `healthcheck.New` - Health check (depends on Globals, Config, Logger,
+   Database)
 6. `middleware.New` - Middleware (depends on Logger, Globals, Config)
 7. `handlers.New` - Handlers (depends on Logger, Globals, Database, Healthcheck)
 8. `server.New` - Server (depends on all above)
@@ -453,7 +457,8 @@ func New(lc fx.Lifecycle, params HandlersParams) (*Handlers, error) {
 
 ### Closure-Based Handler Pattern
 
-All handlers return `http.HandlerFunc` using the closure pattern. This allows initialization logic to run once when the handler is created:
+All handlers return `http.HandlerFunc` using the closure pattern. This allows
+initialization logic to run once when the handler is created:
 
 ```go
 // internal/handlers/index.go
@@ -510,7 +515,8 @@ func (s *Handlers) decodeJSON(w http.ResponseWriter, r *http.Request, v interfac
 ### Handler Naming Convention
 
 - `HandleIndex()` - Main page
-- `HandleLoginGET()` / `HandleLoginPOST()` - Form handlers with HTTP method suffix
+- `HandleLoginGET()` / `HandleLoginPOST()` - Form handlers with HTTP method
+  suffix
 - `HandleNow()` - API endpoints
 - `HandleHealthCheck()` - System endpoints
 
@@ -733,7 +739,8 @@ func New(lc fx.Lifecycle, params ConfigParams) (*Config, error) {
 
 1. **Environment variables** (highest priority via `AutomaticEnv()`)
 2. **`.env` file** (loaded via `godotenv/autoload` import)
-3. **Config files**: `/etc/{appname}/{appname}.yaml`, `~/.config/{appname}/{appname}.yaml`
+3. **Config files**: `/etc/{appname}/{appname}.yaml`,
+   `~/.config/{appname}/{appname}.yaml`
 4. **Defaults** (lowest priority)
 
 ### Environment Loading
@@ -1005,6 +1012,7 @@ var Static embed.FS
 ```
 
 Directory structure:
+
 ```
 static/
 ├── static.go
@@ -1045,15 +1053,13 @@ Templates use Go's template composition:
 
 ```html
 <!-- index.html -->
-{{ template "htmlheader.html" . }}
-{{ template "navbar.html" . }}
+{{ template "htmlheader.html" . }} {{ template "navbar.html" . }}
 
 <main>
     <!-- Page content -->
 </main>
 
-{{ template "pagefooter.html" . }}
-{{ template "htmlfooter.html" . }}
+{{ template "pagefooter.html" . }} {{ template "htmlfooter.html" . }}
 ```
 
 ### Static Asset References
@@ -1214,12 +1220,12 @@ if viper.GetString("METRICS_USERNAME") != "" {
 
 ### Environment Variables Summary
 
-| Variable | Description | Default |
-|----------|-------------|---------|
-| `PORT` | HTTP listen port | 8080 |
-| `DEBUG` | Enable debug logging | false |
-| `DBURL` | Database connection URL | "" |
-| `SENTRY_DSN` | Sentry DSN for error reporting | "" |
-| `MAINTENANCE_MODE` | Enable maintenance mode | false |
-| `METRICS_USERNAME` | Basic auth username for /metrics | "" |
-| `METRICS_PASSWORD` | Basic auth password for /metrics | "" |
+| Variable           | Description                      | Default |
+| ------------------ | -------------------------------- | ------- |
+| `PORT`             | HTTP listen port                 | 8080    |
+| `DEBUG`            | Enable debug logging             | false   |
+| `DBURL`            | Database connection URL          | ""      |
+| `SENTRY_DSN`       | Sentry DSN for error reporting   | ""      |
+| `MAINTENANCE_MODE` | Enable maintenance mode          | false   |
+| `METRICS_USERNAME` | Basic auth username for /metrics | ""      |
+| `METRICS_PASSWORD` | Basic auth password for /metrics | ""      |