feat: Plexum-kimi-provider v0.1 — Moonshot Kimi via coding endpoint

Plexum ProviderPlugin that serves Moonshot Kimi K2.6 ("Kimi for
Coding") via Kimi's Anthropic-compatible coding endpoint at
https://api.kimi.com/coding/v1/messages. Port of openclaw's
extensions/kimi-coding/provider-catalog.ts to Go + Plexum SDK.

Repo structure parallels Plexum-minimax-provider:
- internal/anthropic/    HTTP+SSE Anthropic Messages client, with new
                         UserAgent field (Kimi expects "claude-code/
                         0.1.0" — openclaw plugin parity)
- internal/translate/    canonical ↔ Anthropic translator (re-used
                         shape from MiniMax — no Kimi-specific quirks
                         needed for v1 plain-text path)
- cmd/plexum-kimi-provider-plugin/  ProviderPlugin entry

Declared models (Kimi server accepts all three; plugin normalizes
legacy aliases to the canonical id on the wire):
  kimi-for-coding      (current, default)
  kimi-code            (legacy alias)
  k2p5                 (legacy alias)

HostConfig: api_key (required), base_url (override), user_agent
(default "claude-code/0.1.0"), max_tokens_default (default 8192).

End-to-end verified against the live `sk-kimi-` subscription key:

1. CLI embedded turn 1:    "Hi there! I'm Kimi."
2. CLI embedded turn 2:    "I said hi, I'm Kimi." (multi-turn context OK)
3. Via gateway socket:     {"outcome":"text","text":"...pong"}
4. Via Fabric channel:     alice → bt2-clean → kimi agent → Kimi K2.6 →
                           outbound REST → reply in channel seq=15:
                           "Concise concurrency: goroutines and channels
                            make parallel code readable, safe, and
                            efficient without the usual threading
                            complexity."

Test the bidirectional channel pipeline works with a fresh provider:
Fabric (channel plugin) + Kimi (provider plugin) wired through Plexum
agentloop, MiniMax-style plugin packaging.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

scripts/install.sh

@@ -0,0 +1,77 @@
+#!/usr/bin/env bash
+# Plexum-kimi-provider installer (Phase v0.1).
+#
+# Builds + installs:
+#   ~/.plexum/plugins/plexum-kimi-provider/plexum-kimi-provider-plugin
+#   ~/.plexum/plugins/plexum-kimi-provider/manifest.json
+#
+# Operator then writes the per-profile config:
+#   ~/.plexum/plugins/plexum-kimi-provider/config.json
+#     {"api_key": "sk-kimi-..."}
+#
+# Re-runnable. Profile data + config.json are never touched.
+#
+# Flags:
+#   --profile <p>    Override profile root (default ~/.plexum)
+set -euo pipefail
+
+REPO="$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")/.." && pwd)"
+PROFILE_DIR="${HOME}/.plexum"
+
+while [[ $# -gt 0 ]]; do
+    case "$1" in
+        --profile) PROFILE_DIR="$2"; shift 2 ;;
+        -h|--help) sed -n '2,/^set -euo/p' "$0" | sed -n '/^#/p' | sed 's/^# \{0,1\}//'; exit 0 ;;
+        *) echo "unknown flag: $1" >&2; exit 2 ;;
+    esac
+done
+
+log() { printf '\033[1;34m[kimi-install]\033[0m %s\n' "$*"; }
+command -v go >/dev/null || { echo "go not found on PATH" >&2; exit 1; }
+
+PLUGIN_DIR="${PROFILE_DIR}/plugins/plexum-kimi-provider"
+mkdir -p "${PLUGIN_DIR}"
+
+cd "${REPO}"
+VERSION="$(git describe --tags --always 2>/dev/null || echo dev)"
+LDFLAGS="-X main.Version=${VERSION}"
+log "building plexum-kimi-provider-plugin (v=${VERSION})"
+CGO_ENABLED=0 go build -ldflags="${LDFLAGS}" \
+    -o "${PLUGIN_DIR}/plexum-kimi-provider-plugin" \
+    ./cmd/plexum-kimi-provider-plugin
+
+cat > "${PLUGIN_DIR}/manifest.json" <<'EOF'
+{
+  "name": "plexum-kimi-provider",
+  "version": "0.1.0",
+  "activation": "lazy",
+  "executable": "plexum-kimi-provider-plugin",
+  "contracts": {
+    "provider": {
+      "models": ["kimi-for-coding", "kimi-code", "k2p5"]
+    }
+  }
+}
+EOF
+
+cat <<EOF
+
+[kimi-install] done.
+  plugin binary: ${PLUGIN_DIR}/plexum-kimi-provider-plugin
+  manifest:      ${PLUGIN_DIR}/manifest.json
+  models:        kimi-for-coding (+ legacy aliases: kimi-code, k2p5)
+  endpoint:      https://api.kimi.com/coding/v1/messages
+
+Next steps:
+  1. Write API key:
+       cat > ${PLUGIN_DIR}/config.json <<JSON
+       {"api_key": "sk-kimi-..."}
+       JSON
+       chmod 600 ${PLUGIN_DIR}/config.json
+  2. Allow plugin:
+       Add "plexum-kimi-provider" to ${PROFILE_DIR}/plexum.json's
+       .plugins.allow array
+  3. Point an agent at Kimi:
+       plexum agent-add --model kimi-for-coding <agent-id>
+  4. systemctl --user restart plexum
+EOF