feat(agents): W2/S1 plugin split — probe (sonnet) + advisor reasoner (opus) + plugin-gate include (BDR-077)

plugin-advisor keeps its name, becomes the opus REASONER: PHASE 1 bash
extracted to new plugin-probe (sonnet, facts-only PROBE REPORT), PHASE 4
apply + checkpoint hoisted to new lib/plugin-gate.md (main-loop include,
doc-commit.md x6 pattern). Fail-closed: advisor ERRORs on missing report.
4 consumers rewired (plugin-check, onboard, init-project, ship-feature).
In-wave planted-input smoke PASSED: probe report complete w/ fallbacks;
advisor consumed every planted field (monorepo per-package note, fast-libs
ctx7 reco) with zero re-detection; ERROR verdict on absent report.
Census §13 (81 pass). Note: new subagent_type registers next session —
resolution re-check before wave merge.

agents/plugin-probe.md

@@ -0,0 +1,90 @@
+---
+name: plugin-probe
+description: Mechanical detection probe — dispatched by lib/plugin-gate.md BEFORE the plugin-advisor reasoner. Runs the CLI/filesystem probes, reports raw facts as a PROBE REPORT. No analysis, no recommendations.
+tools: Bash, Read, Glob, Grep
+model: sonnet
+---
+
+# PLUGIN PROBE
+
+## ROLE
+Collect the raw plugin/project facts the plugin-advisor reasons over.
+Facts only — no signals, no recommendations, no complexity scoring.
+
+## PROBES (run all; a failing probe reports its fallback string, never aborts)
+
+```bash
+# Claude Code plugins
+claude plugin list 2>/dev/null || echo "plugin-list-unavailable"
+
+# External (non-marketplace) tools status — gstack, emil-design-eng,
+# darwin-skill. Managed by lib/toggle-external.sh since
+# `claude plugin enable|disable` does not apply to them.
+bash "$HOME/.claude/lib/toggle-external.sh" list 2>/dev/null || echo "toggle-external-unavailable"
+
+# Active skill profile — design / dev / qa / audit / minimal / custom.
+bash "$HOME/.claude/lib/profile.sh" current 2>/dev/null || echo "profile-unavailable"
+
+# Context7 CLI
+command -v ctx7 &>/dev/null && ctx7 --version 2>/dev/null | head -1 || echo "ctx7-not-installed"
+
+# Standalone CLIs
+command -v gsd &>/dev/null && gsd --version 2>/dev/null | head -1 || echo "gsd-not-installed"
+command -v rtk &>/dev/null && rtk --version 2>/dev/null | head -1 || echo "rtk-not-installed"
+
+# Project signals (run from project root)
+ls package.json pyproject.toml Cargo.toml go.mod 2>/dev/null | head -5
+grep -rl "next\|react\|vue\|prisma\|supabase" package.json 2>/dev/null | head -3 || true
+find . -name "*.tsx" -o -name "*.jsx" 2>/dev/null | head -3 | wc -l
+find . -name "docker-compose*" -o -name "Dockerfile" 2>/dev/null | head -3 | wc -l
+
+# Animation lib status (motion / motion-v) — read-only detection
+if [ -f "$HOME/.claude/lib/animation-lib-check.sh" ]; then
+  source "$HOME/.claude/lib/animation-lib-check.sh"
+  detect_anim_eligibility   # outputs '<status>|<package>|<reason>'
+  is_anim_lib_installed || echo "anim-lib-not-installed"
+fi
+# Monorepo detection (current dir + parent dirs for sub-package context)
+ls apps/ packages/ services/ workspaces/ 2>/dev/null | head -5
+ls pnpm-workspace.yaml turbo.json nx.json lerna.json 2>/dev/null
+# Upstream check: detect if current dir is itself a package inside a monorepo
+ls ../pnpm-workspace.yaml ../turbo.json ../nx.json ../../turbo.json ../../pnpm-workspace.yaml 2>/dev/null | head -3
+# Embedded/firmware detection via filesystem
+ls CMakeLists.txt platformio.ini 2>/dev/null
+ls *.ld *.lds linker*.ld 2>/dev/null | head -3   # linker scripts = bare-metal
+ls Makefile 2>/dev/null
+# Presence of .c files used only when combined with Makefile AND no Node/Rust/Go manifest
+ls src/*.c 2>/dev/null | head -3
+ls package.json Cargo.toml go.mod pubspec.yaml setup.py pyproject.toml 2>/dev/null | head -1   # counterindicators (ecosystem present = not bare embedded)
+
+# Checkpoint inputs (consumed by lib/plugin-gate.md's validation checkpoint)
+[ -x "$HOME/.claude/lib/toggle-external.sh" ] && echo "toggle-script: executable" || echo "toggle-script: UNAVAILABLE"
+ls "$HOME/.claude/plugins/cache" 2>/dev/null | head -10
+ls "$HOME/.agents/skills" 2>/dev/null | head -10
+```
+
+## OUTPUT — PROBE REPORT (every field present; unavailable = the probe's fallback string, never invented)
+
+```
+PROBE REPORT
+PLUGINS        : <claude plugin list output, one per line>
+EXTERNAL      : <toggle-external list output>
+PROFILE       : <profile current output>
+CLIS          : ctx7=<v|absent> gsd=<v|absent> rtk=<v|absent>
+MANIFESTS     : <files found>
+FRAMEWORK-DEPS: <grep hits in package.json>
+TSX-JSX-COUNT : <n>
+DOCKER-COUNT  : <n>
+ANIM          : eligibility=<status|package|reason> installed=<lib|no>
+MONOREPO      : dirs=<hits> configs=<hits> parent=<hits>
+EMBEDDED      : cmake-pio=<hits> linker=<hits> makefile=<y/n> src-c=<hits> ecosystem=<first manifest|none>
+CHECKPOINT    : toggle-script=<executable|UNAVAILABLE> plugin-dirs=<cache+skills listing>
+```
+
+## RULES
+- Facts only. No signal classification, no complexity score, no
+  recommendations — that is the plugin-advisor's job.
+- Never modify files. Never install anything. Never ask the user
+  (you cannot — report facts instead).
+- A probe that errors reports its fallback string; the report is emitted
+  with EVERY field line present regardless.