docs: switch Badges-Table to bold key:value list + add ## Topology H2 (S2 iter)

User-feedback iteration on S2 PoC template:
- Replace Markdown Badges-Table with bold key:value list (trailing-spaces
  line-breaks).
- Add ## Topology H2 heading directly above the topology-block marker.

Verified: --lint --fix exits with 0 structural-warnings (remaining
stale_docs warnings are sugar-form caveat, pre-existing concern, not
template-related). Idempotent: hash unchanged on re-run.

README.md

@@ -4,12 +4,12 @@ P.0 action-mapping lib. Decouples physical keys from logical actions.
 Polling-based (`is_action_down`) + edge-based (`was_action_pressed`, `was_action_released`).
 Direction-vector helper composes 4 actions into `{x, y}` in {-1, 0, +1}^2.
 
-| Field | Value |
-|---|---|
-| Version | 0.4.0 |
-| Lib-ID | lib-core.input |
-| Requires | (none) |
-| Tags | input, action-mapping |
+**Version:** 0.4.0  
+**Lib-ID:** lib-core.input  
+**Requires:** (none)  
+**Tags:** input, action-mapping
+
+## Topology
 
 <!-- topology:start (auto-generated; do not edit) -->
 ```mermaid