fix(template): parameterize scaffold with __PROJECT_NAME__/__MODULE_PATH__ (gitea-mcp#44)

template-go-web was seeded from the real `hostexecutor` project and never
parameterized: go.mod hardcoded `module gitea.d-ma.be/mathias/hostexecutor` and
`hostexecutor` appeared throughout (cmd dir, Dockerfile, Taskfile, CI, context
docs). create_project_from_template therefore substituted nothing and returned
a "no placeholders" partial_failure on the zero-config default path.

Replaced the full module path with __MODULE_PATH__ and the bare project name
with __PROJECT_NAME__ (incl. renaming cmd/hostexecutor → cmd/__PROJECT_NAME__),
matching the substitution the tool performs. Also drops the stale gitea.d-ma.be
host (the placeholder resolves to git.d-ma.be/<owner>/<name>).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Dockerfile

@@ -5,7 +5,7 @@ RUN go install github.com/a-h/templ/cmd/templ@latest
 COPY go.mod ./
 RUN go mod download
 COPY . .
-RUN templ generate && CGO_ENABLED=0 go build -trimpath -ldflags='-s -w' -o /out/app ./cmd/hostexecutor
+RUN templ generate && CGO_ENABLED=0 go build -trimpath -ldflags='-s -w' -o /out/app ./cmd/__PROJECT_NAME__
 
 FROM gcr.io/distroless/static-debian12:nonroot
 COPY --from=build /out/app /app