The numbering is the flow: decisions are 02, design is 03

papa-hq reads 01 research -> 03 decision -> 02 design. The order is a
scar, not a choice: 02-DESIGN existed from its initial commit, and when
adr/ was finally promoted on 2026-07-13 it took the next free number
rather than its place in the sequence. By then design was too settled to
renumber.

hal-hq was three commits old, so it is not. adr/ becomes 02-DECISIONS and
02-DESIGN becomes 03-DESIGN, and following the folder numbers now walks
the process in the order it happens: research produces a decision, the
decision authorises a design.

00-GENESIS becomes 00-META, matching papa's rename from the same
restructure.

Every path reference rewritten across documents, frontmatter, playbooks
and skills. All links resolve; all 58 frontmatter blocks parse and their
path fields still point at files that exist.

02-DECISIONS/0002-everything-is-a-module.md

@@ -0,0 +1,73 @@
+---
+status: accepted
+date: 2026-03-14
+deciders: jochen
+reconstructed: true
+---
+
+# 2. Everything is a module, and one manifest describes all of them
+
+> Reconstructed after the fact from the evidence cited below.
+
+## Context
+
+The mesh carries several kinds of thing: containerised services with data and ports, pure
+capability providers with no service at all, and bare markers whose only content is that a
+node has them. Before this decision these were separate concepts with separate handling —
+the earlier vocabulary was *capabilities*, and services were installed by a different path
+than tools.
+
+Every distinct kind of thing needs its own install path, its own change detection, its own
+place in the delivery pipeline, and its own documentation. Three kinds means three of each,
+and every new feature has to be built three times or, more commonly, once — leaving two kinds
+quietly unsupported.
+
+## Considered options
+
+1. **Separate concepts per kind** — a service registry, a tool registry, a node feature flag
+   list. Rejected: it is what existed, and the cost was paid in every cross-cutting change.
+2. **One manifest, kind inferred from directory contents.** Chosen.
+3. **One manifest with an explicit `type:` field on every module.** Partly adopted — a service
+   still declares itself — but the general rule became inference, because a declared list and
+   the directory it describes drift, and the directory is the one that is true.
+
+## Decision
+
+Everything the mesh installs is a **module**: a directory with a manifest. The manifest
+declares identity, environment variables, what the module provides, what it requires, and how
+it is exposed. What kind of module it is follows from what the directory contains:
+
+| Contains | Is |
+|---|---|
+| a compose definition | a service |
+| a tools directory | a capability provider |
+| a daemon or unit directory | a long-running process |
+| a configs directory | a source of managed files |
+| nothing but a manifest | a flag — presence is the whole content |
+
+A module may be several of these at once. Each is a **feature**, and the delivery pipeline
+addresses features, not modules.
+
+The mesh's own components are modules on exactly these terms. They get no privileged install
+path, no separate registry, and no exemption from the pipeline.
+
+## Consequences
+
+- One mechanism to learn, one to document, one to fix. A pipeline improvement reaches
+  everything the mesh carries.
+- Dogfooding stops being a discipline and becomes structural: if the mesh's own components
+  need an exception, the machinery is unfinished, and that is visible immediately.
+- Feature detection from directory contents means a directory rename silently changes what a
+  module *is*. This has bitten repeatedly — a hook named for a feature the module does not
+  have is skipped without complaint.
+- The manifest becomes load-bearing and grows. It is now the largest single point of
+  coupling in the mesh.
+
+## References
+
+- `Rename capabilities → modules across the entire codebase`, 2026-03-14.
+- `Merge fail2ban, ufw, firewall apps into modules`, 2026-03-15 — the first modules to arrive
+  by conversion rather than by creation.
+- Knowledge base: `modules`, `modules/manifest-reference`, `conventions/modules`.
+- The rename-breaks-detection shape: `troubleshooting/hooks-named-for-missing-feature`,
+  `troubleshooting/health-check-tools-index-false-positive`.