Server: web client under /app/ (D-132), analytics E-34 trends and E-35 forecast (D-133)

Part A (D-132): KVITT_WEB_DIR (default /app) served under /app/ by a small handler: /app redirects to
/app/, app routes fall back to index.html, a missing assets/* file is 404, assets cached immutable,
index.html no-store, the app's own CSP plus nosniff, DENY and no-referrer. Unsafe paths never reach the
file system. /app paths count against the unauthenticated per-IP limit. Without the directory every /app
path stays 404 not_found. server/Dockerfile gains a Node 24 LTS stage (pinned by digest) building web/,
passed through the Rust stage so npm and rustc never run at once on the Pi 3; the build context is the
repository root with an allowlist .dockerignore (server/.dockerignore removed); workflow, build-images.sh
and infra/dev/build.sh follow.

Part B (D-133): GET /analytics/trends (E-34) and GET /analytics/forecast (E-35), authenticated, read-only,
SQL month buckets; rules (half-up average, trailing 3-month moving average, percent against the rounded
average, template occurrence per month) in kvitt-domain::analytics. OpenAPI, examples, contracts-check
and tests updated (35 operations).

Cargo.lock: rustls-webpki 0.103.16 and webpki-root-certs 1.0.10 (RUSTSEC-2026-0382, -0383) so that
cargo audit passes.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01TQd3pEP9UeN2uifbHknQ7B

server/Cargo.lock

@@ -1838,9 +1838,9 @@ checksum = "eec689c0bc40ff2458a5977b6619cb718087084a18e02a131c599b62d05e1a5f"
 
 [[package]]
 name = "rustls-webpki"
-version = "0.103.15"
+version = "0.103.16"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f3c3cf1d8b1e7d4927e2d154c3fcb02979afb9939629c62cd9048d4f07b60ac2"
+checksum = "4443b1b6d39d7c663139942cc4558262562d2c84123bb6282ef177009ca8b281"
 dependencies = [
  "aws-lc-rs",
  "ring",
@@ -2868,9 +2868,9 @@ dependencies = [
 
 [[package]]
 name = "webpki-root-certs"
-version = "1.0.9"
+version = "1.0.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b96554aa2acc8ccdb7e1c9a58a7a68dd5d13bccc69cd124cb09406db612a1c9b"
+checksum = "58ec80e73fd8baf57bf0d9615554c75348bda990d6d5bbeab964dd068319fecb"
 dependencies = [
  "rustls-pki-types",
 ]