feat: add D.intelligence Agent Corps (9 skills + shared infra)

Add 9 agent skills (#70-#77, #88) for D.intelligence business operations:
brand guardian, brand editor, doc secretary, quotation manager, service
architect, marketing manager, back office manager, account manager, and
skill update meta-agent. Includes shared Python package (dintel), reference
docs, document/quotation templates, service module CSVs, cross-device
installer, and comprehensive user guide.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

custom-skills/70-dintel-brand-guardian/README.md

@@ -0,0 +1,57 @@
+# 70-dintel-brand-guardian
+
+**Agent #70** in the D.intelligence Agent Corps | v1.1.0
+
+## What it does
+
+Brand Guardian is the strategic brand governance layer for D.intelligence. It reviews ALL D.intelligence content for brand compliance using a 100-point checklist:
+
+| Category | Points | Scope |
+|----------|--------|-------|
+| Tone & Manner | 25 | Professional/Scientific/Practical/Outcome tone, prohibited expressions |
+| Message Structure | 25 | 4-step framework, KPIs, Before/After, actionable CTAs |
+| Service Architecture | 25 | Module codes (A1-G4), category tags (DI/MD/MPO/BVT), 3-Phase accuracy |
+| Brand Identity | 25 | "파트너" positioning, Core Values, no brand violations |
+
+## Triggers
+
+Autonomy level: **Auto** — activates on any D.intelligence content review or creation request.
+
+Detection keywords:
+- "D.intelligence", "디인텔리전스", "brand review", "brand check"
+- "톤앤매너 검토", "브랜드 검토", "제안서 검토", "콘텐츠 검토"
+- Module codes (A1-A6, T1-T7, G1-G4)
+- Category tags (DI, MD, MPO, BVT)
+- Tagline "Analysis, Treatment & Growth"
+
+## Structure
+
+```
+70-dintel-brand-guardian/
+├── code/
+│   └── CLAUDE.md          # Claude Code directive (condensed quick-reference)
+├── desktop/
+│   └── SKILL.md           # Full skill definition for Claude Desktop
+├── shared/
+│   └── (reserved)         # Future shared assets
+└── README.md              # This file
+```
+
+## Relation to Other Agents
+
+Part of the **D.intelligence Agent Corps** (agents 70-77 + meta-agent 88, prefix `dintel-`):
+
+- **#70 dintel-brand-guardian** (this agent) — Brand governance, content compliance
+- **#70 dintel-brand-editor** (legacy: `70-dintelligence-brand-editor`) — Notion content editing
+- Other agents: TBD as Agent Corps Phase 0 progresses
+
+Shared Python environment: `dintel-shared/src/dintel/brand.py` for brand constants used across all dintel- agents.
+
+## Source
+
+Migrated from `D.intelligence Service Package/dintelligence-brand-guardian/SKILL.md` (v1.0) with the following changes in v1.1.0:
+- Renamed from `dintelligence-brand-guardian` to `dintel-brand-guardian`
+- Added Agent Corps context (Agent #70)
+- Added Universal Guardrails section
+- Added reference to shared Python brand constants
+- Added reference to Notion schema