feat: initial stats-cohort-size v0.1.0 (stats.cohort_size@0.1.0)

Resolve the size of an addressee cohort (e.g. "Berliner KMU",
"Gastronomie deutschlandweit").

v0.1.0 ships a five-entry built-in lookup for the F∆I Law-Heatmap
pilot corpus:

  berlin-kmu, de-kmu, gastro-de, handwerk-be, bauwirtschaft-be

Each entry carries (count, year, source, tier). Tier follows the
Studie §6.7 Regel-der-niedrigsten-Stufe: T1 when from DESTATIS
Unternehmensregister, T2 when from a Verband source.

Reuse-lens: any quantitative analysis that needs cohort sizing —
market research, audience targeting, public-health tracking.

Pure in-WASM, zero filesystem, zero network.

Reserved for next versions:

  - 0.2: DESTATIS GENESIS-API adapter — requires
         net: ["genesis.destatis.de"] permission. Interface stays
         the same; the static lookup becomes the fallback when
         the API is unreachable.
  - 0.3: WZ-Code-resolved sub-cohorts (e.g. "berlin-kmu-wz56").

Signed-off-by: flemming-it <sf@flemming.it>

module.yaml

@@ -0,0 +1,42 @@
+schema_version: 3
+provider: chain
+name: stats-cohort-size
+version: 0.1.0
+
+# Resolve the size of an addressee cohort (e.g. "Berliner KMU
+# nach WZ-Code", "Gastronomie deutschlandweit").
+#
+# v0.1.0 ships a built-in stub table for the five pilot cohorts.
+# v0.2 adds a DESTATIS GENESIS-API adapter (capability requires
+# `net` permission); the API surface here stays identical.
+#
+# Reuse-lens: any quant analysis that needs cohort sizing —
+# market research, audience targeting, public-health tracking.
+provides:
+  - capability: stats.cohort_size
+    version: 0.1.0
+
+inputs:
+  cohort_id:
+    type: text
+    description:
+      en: |
+        Cohort identifier. v0.1.0 recognises:
+          berlin-kmu, de-kmu, gastro-de, handwerk-be, bauwirtschaft-be
+      de: |
+        Kohorten-Identifier. v0.1.0 kennt:
+          berlin-kmu, de-kmu, gastro-de, handwerk-be, bauwirtschaft-be
+
+outputs:
+  cohort:
+    type: json
+    description:
+      en: |
+        { id, count, year, source, tier }.
+        tier ∈ {T1, T2} — T1 when DESTATIS, T2 when Verband-source.
+      de: |
+        { id, count, year, source, tier }.
+
+# v0.1 stub: no permissions. v0.2 DESTATIS adapter needs:
+#   net: ["genesis.destatis.de"]
+permissions: []