feat(wallet,content,seed): Fedimint dual-ecash, paid content streaming, seed ceremony

- Fedimint ecash alongside Cashu: fedimint-clientd (fmcd) HTTP bridge,
  fedimint_client, fedimint RPC, wallet wiring
- Paid peer content: content invoices + streaming content server + content RPCs
- Seed-phrase ceremony/reveal RPCs and CLI ceremony tool
- LND wallet, mesh status/messaging, app-stack (netbird HTTPS), and
  decoupled-update wiring; Fedimint Client core app in catalog

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

docker/fmcd/Dockerfile

@@ -0,0 +1,21 @@
+# fmcd (Fedimint client daemon) runtime image.
+#
+# The fmcd binary is built from source (github.com/minmoto/fmcd v0.8.0,
+# fedimint-client 0.8.2 — iroh-capable) with Rust 1.86.0, then copied in here.
+# Base must match the build host's glibc (Debian trixie / glibc 2.41).
+# Binary is dynamically linked against libstdc++ (statically-bundled rocksdb)
+# and uses rustls (no openssl). Build context must contain the `fmcd` binary.
+FROM debian:trixie-slim
+
+RUN apt-get update \
+    && apt-get install -y --no-install-recommends ca-certificates libstdc++6 \
+    && rm -rf /var/lib/apt/lists/*
+
+COPY fmcd /usr/local/bin/fmcd
+COPY fmcd-run /usr/local/bin/fmcd-run
+RUN chmod +x /usr/local/bin/fmcd /usr/local/bin/fmcd-run
+
+EXPOSE 8080
+# Resilient launcher (retries on join failure instead of crash-looping).
+# All config is read from FMCD_* env vars.
+ENTRYPOINT ["fmcd-run"]