docs: add docs-as-code process and one ADR per feature

docs/docs-as-code.md defines the workflow; docs/adr holds 31 ADRs
(retroactive, reconstructed from code and changelog) with a template and
index. docs/check-docs.sh validates ADR structure, index, cited code
paths, relative links and CLAUDE.md/AGENTS.md sync.

docs/adr/0024-cli-on-shared-core.md

@@ -0,0 +1,22 @@
+# 0024. A CLI front end on the same Core
+
+- **Status:** Accepted
+- **Area:** Distribution
+- **Recorded:** 2026-11-03 (retroactive: reconstructed from code, comments and changelog)
+
+## Context
+
+Scripting, headless servers and quick manual verification need the wallet without a GUI.
+
+## Decision
+
+`src/Cli` exposes `create`, `restore`, `restore-xpub`, `restore-address`, `info`, `sync`, `send`, `servers`, `reset-certs`, `newseed` and `addresses` on the same `Core` as the GUI, with `--net`, `--file`, `--server host:port` and `--ssl` options. The default wallet file is `~/.palladium-wallet/<network>/wallets/default.wallet.json`.
+
+## Consequences
+
+- Core behaviour is exercised outside the GUI.
+- Passwords on the command line are visible to other local users and shell history; the CLI is a developer tool, not a hardened interface.
+
+## References
+
+- `src/Cli/Program.cs`