docs: reset authority to current Career OS product model

ARCHITECTURE.md

@@ -1,70 +1,125 @@
-# OfferU 架构边界
-
-```text
-TypeScript React UI / Client Interaction
-              │ typed HTTP API
-              ▼
-Python FastAPI Career Runtime
-  Profile · Job · Application · Artifact
-  Event · Candidate · CareerTask
-              │ Operation Registry
-              ▼
-External Agent Runtime
-  Pi · Replay · Codex · DSH adapter
-
-Tauri / Rust = desktop shell and process lifecycle only
-```
+
+# OfferU Architecture
+
+Status: **CURRENT ARCHITECTURE AUTHORITY**  
+Updated: 2026-09-23
+
+OfferU is a local-first Career OS. The desktop product is the primary user experience; local Agents are replaceable reasoning engines attached to the same deterministic career control plane.
+
+## System boundary
+
+~~~
+                    OfferU Desktop
+          Today · Pipeline · Job · Profile
+                         │
+             guided intent / user action
+                         │
+              ┌──────────┴──────────┐
+              │                     │
+     External local Agent      OfferU fallback Agent
+        (preferred)               (optional)
+              │                     │
+              └──────────┬──────────┘
+                         │
+         OfferU Skill + optional Career Skills
+                         │
+                  Agent Tool Surface
+                         │
+                Operation Registry
+          schema · permission · proposal
+             idempotency · audit
+                         │
+                  Career Runtime
+      Profile · Job · Application · Resume
+       Interview · Evidence · Events · Memory
+                         │
+                 local SQLite / files
+~~~
+
+Browser capture, email sync, automation and direct human UI actions join the same control plane; they do not maintain parallel business truth.
+
+## Four authorities
+
+- **Reasoning authority** — exactly one active Agent per Agent Run. Prefer a verified local Agent already owned by the user; OfferU may provide a fallback.
+- **Execution authority** — the Operation Registry controls governed capabilities, validation, side effects, proposals, idempotency and audit.
+- **Truth authority** — the Python Career Runtime owns persistent career state.
+- **High-risk approval authority** — the user or an explicit deterministic product policy. An Agent cannot approve its own protected mutation.
+
+## Agent hosts and Skills
+
+Agent hosts may be Codex, WorkBuddy/CodeBuddy, Claude Code, OpenCode, OMP, Pi, Gemini or future compatible hosts.
+
+OfferU detects host capability from code/probes rather than assuming parity. A host may be a Skill host, a hosted runtime/executor, both, unavailable or only partially compatible.
+
+When the host supports Agent Skills, OfferU projects its Skill and allows composition with installed resume/recruiting/interview/career Skills. Third-party Skills provide methodology; OfferU remains the state and side-effect authority.
+
+## Tool surface
+
+The broad Operation Registry is **not** the model-facing tool list.
+
+~~~
+Operation Registry
+  └─ Agent Tool Surface
+      └─ Active Skill Surface
+~~~
+
+Agents discover compact Skill metadata first and load the relevant operation schemas on demand. Developer/audit paths may expose the full Registry, but beginner Agent flows should not.
+
+See [Tool Surface V2](./docs/architecture/2026-09-22-tool-surface-v2.md).
 
 ## Truth flow
 
-```text
+~~~
 Observe
   ↓
-Event / Candidate
+Event / Evidence / Candidate
   ↓
-Career Runtime understands state
+Career Runtime validates / associates
   ↓
-CareerTask plans work
+Agent or deterministic policy recommends next action
   ↓
-Operation executes or proposes
+Operation executes or creates Proposal
   ↓
-verified state / artifact is committed
+review / confirmation when required
   ↓
-Today and Pipeline project the same state
-```
-
-Agent 负责 reasoning、planning、tool selection 和研究编排；不能直接拥有职业事实。Operation Registry 负责 capability、权限、dry-run、确认和审计。Python Domain Runtime 是 Career Truth 的唯一来源。自然语言“我已更新”不是成功证明，只有成功提交的 Operation 才能改变正式状态。
+verified state / artifact
+  ↓
+Today / Pipeline / Job / Profile re-project the same truth
+~~~
 
-## 领域对象
+Natural-language “done” is never the proof of completion.
 
-优先围绕 `Profile`、`Job`、`Application`、`Artifact`、`Event`、`Candidate`、`CareerTask` 表达需求。Today、Pipeline 和 Agent UI 是 projection 或执行界面，不复制同一业务状态。
+## Browser and email
 
-## Resume Workspace
+Default job acquisition is explicit current-page capture. Smart Fill may assist safe fields after review but never silently submits an application.
 
-岗位简历工作区复用现有 `Resume`、`ResumeSection`、`ResumeOptimizationProposal` 和 `ResumeVersion`，不创建平行的文档状态：
+Email and other authorized channels create evidence/signals and reviewable progress candidates. They do not directly overwrite Pipeline state.
 
-```text
-Career Evidence / Profile
-        ↓
-Master Resume
-        ↓ source_resume_id + target_job_id
-Job Tailored Resume
-        ↓
-Application Packet projection
-```
+## Built-in runtime code
 
-编辑器、实时预览和 PDF 都读取同一份结构化 Resume 内容。AI 只生成 Proposal；逐条接受/拒绝、手动编辑、排序、可见性和模板修改都通过 Resume Operation Registry。`workspace_snapshot_hash` 用于阻止过期 Proposal 覆盖用户最新修改，`ResumeVersion` 保存可回看的岗位版本与来源。
+Legacy/internal runtime workers may remain for fallback, replay, compatibility or bounded executor use. Their existence does not make them the Career Truth owner or the mandatory product shell.
 
-OfferU 不创建 `ResumeAgent`。岗位简历准备是 `CareerTask`，由现有 Agent Runtime 选择受控 Operation 执行。Job Detail 是进入 Workspace 的主要入口，Today / Pipeline 只投影同一 Application、Event 和 Packet 状态。
+## Stable technology boundary
 
-## 自动化
+~~~
+React / TypeScript = product UI
+Python / FastAPI = Career Runtime + Operation Registry + deterministic policy
+Tauri / Rust = desktop shell, lifecycle, installer and OS integration
+Agent hosts/runtimes = replaceable reasoning/execution engines
+SQLite = local career data
+~~~
 
-```text
-Event → Rule → CareerTask → Agent / deterministic runtime → Operation
-```
+Do not introduce a second business backend or duplicate Career Truth to match an Agent framework.
 
-低风险读取、研究、计算和候选生成可以自动执行；正式 Career Truth 变更仍经过事实门和用户确认；外部不可逆动作始终需要明确用户操作。
+## Safety invariants
 
-## Provider 与数据来源
+- Agent output is candidate/draft until accepted through the correct path.
+- Important state mutations are reviewable and auditable.
+- External irreversible actions remain user-controlled.
+- No Agent may self-confirm a protected proposal.
+- Credentials do not enter Agent context.
+- Provider/host failures are explicit.
+- Browser/email integrations cannot create hidden business state.
+- Historical eval or fixture success cannot be presented as current live capability.
 
-Replay/Fixture 是显式的合成数据模式，必须在 UI 和产物中标记，不能冒充实时市场数据。Live Provider 失败时保留失败或 blocked 状态，允许用户改用 Fixture 验证本地产品链，但不能静默降级成成功。
+Current product interaction authority: [Current Product North Star](./docs/product/current-product.md).