docs(vibe): bootstrap vibe/ knowledge tree + ecosystem AGENTS.md

Add a root AGENTS.md (ecosystem map of factory/tools/cms + agent operating
rules + the persona cohort & workflow) and a new vibe/ knowledge base for LLM
agents, modeled on tree-docs conventions and the factory house style.

vibe/ folders (each with a README hub + contribution rules):
- ADR/      optimized MADR-lite; canonical home going forward (doc/adr stays historical)
- PRD/      one subfolder per PRD, mandatory STATUS.md, QA strategy for big ones
- investigations/  single INV-NNN-slug.md, or stub + folder w/ notebooks
- guidebooks/      tree-docs maps; lab-ecosystem guidebook of factory+tools+cms
- runbooks/        [AGENT]/[HUMAN] step procedures (EN; doc/runbooks stays FR)
- shareouts/       dated FR handouts (decks/mp4)

Seed content (first ADR + PRD): a safe, production-like environment to rehearse
risky changes and recovery without touching real prod — local-only sandbox
(k3d + arm64 VMs) with a hard prod/sandbox isolation boundary. Includes
INV-001 (prod blast-radius couplings), the ecosystem guidebook, and a FR shareout.

Conventions enforced: no-tombstone rule, breadcrumb spine, bidirectional
cross-links, theme:base mermaid (MCP-validated) + ordered-list-after-diagram.
Built with a Workflow + persona cohort; 24 files, zero dead links.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

vibe/ADR/README.md

@@ -0,0 +1,45 @@
+[vibe](../README.md) > **ADR**
+
+# Architecture Decision Records
+
+> **Status**: 🟢 Active
+> **Last Updated**: 2026-06-23
+> **Related**: [vibe/PRD](../PRD/README.md) · [vibe/Investigations](../investigations/README.md)
+> **Historical**: [doc/adr](../../doc/adr/README.md) (foundational infra) · [ansible/.../docs/adr](../../ansible/arcodange/factory/docs/adr/) (dated infra ADRs)
+
+`vibe/ADR/` is the **canonical home for Architecture Decision Records going forward**. The format is MADR-lite: one short, self-contained Markdown file per decision, focused on the *why* rather than the *how*. Use the [`_template.md`](_template.md) skeleton to start a new one.
+
+## Where ADRs live
+
+There are three ADR locations in this repo. Only the first accepts new records; the other two are read-only history kept for context.
+
+| Location | Role | Accepts new ADRs? |
+| --- | --- | --- |
+| `vibe/ADR/` (this folder) | Canonical, MADR-lite, going forward | ✅ Yes |
+| [`doc/adr/`](../../doc/adr/README.md) | Foundational infrastructure ADRs (DNS, k3s, CI/CD, Vault, telegram-gateway auth) | ❌ Historical |
+| [`ansible/arcodange/factory/docs/adr/`](../../ansible/arcodange/factory/docs/adr/) | Dated infra ADRs (network, CI/CD, Longhorn PVC recovery, internal DNS) | ❌ Historical |
+
+When a new decision *supersedes* one of the historical records, write the new ADR here, set the old one's status note to `Superseded by ADR-NNNN`, and cross-link both ways.
+
+## Rules
+
+- **One file per decision**, named `NNNN-kebab-title.md` (zero-padded sequence, e.g. `0001-safe-prod-like-environment.md`).
+- **The body is immutable once `Accepted`.** A decision is a historical fact: do not rewrite the Context/Decision/Consequences after acceptance. The *only* mutation allowed on an accepted ADR is its **status** (e.g. flipping `Accepted` → `Superseded`).
+- **Statuses**: `Proposed` (under discussion) → `Accepted` (decided, body frozen) → `Superseded` (replaced; points to the successor ADR). A `Proposed` ADR may still be edited freely.
+- **No-tombstone rule.** Each file reads as currently true. Never leave "previously X, now Y", changelog lines, or "updated to ..." notes inside an ADR — git history is the audit trail. A superseded ADR keeps its original frozen body; the supersession is recorded only in its status line and the successor's References.
+- **PR cross-link both ways.** The ADR References section links the PR that introduced it; the PR description links back to the ADR. Keep links bidirectional.
+
+## Index
+
+| # | Title | Status | Date |
+| --- | --- | --- | --- |
+| [0001](0001-safe-prod-like-environment.md) | Safe, production-like environment | 🟢 Accepted | 2026-06-23 |
+
+## Rules to contribute
+
+1. Copy [`_template.md`](_template.md) to `NNNN-kebab-title.md` using the next free sequence number and delete the top HTML-comment note.
+2. Fill in the blockquote (Status/Date/Deciders), then Context, Decision, Consequences, Alternatives considered, QA & validation, References.
+3. Open the ADR with status `Proposed`. Flip it to `Accepted` once the decision is settled — and from that point treat the body as frozen.
+4. Add a row to the Index table above (newest at the bottom to preserve chronological numbering).
+5. In the PR that lands the ADR, link to the ADR file; in the ADR's References, link back to the PR. Bidirectional links are mandatory.
+6. If this ADR supersedes a historical one in `doc/adr/` or the Ansible ADR folder, update the old record's status note and cross-reference both directions.