Update docs to reflect convention-to-SEP evolution

The "MCP Skills Convention v0.1" (issue modelcontextprotocol#43, now closed) graduated into
the draft Skills Extension SEP (PR modelcontextprotocol#69). Update docs to reflect this:

- README: work tracking row now shows SEP with Peter as champion,
  success criteria notes the SEP as current direction
- approaches.md: status note under Central Tension, status banner on
  Approach 6 noting it graduated to the SEP
- skill-uri-scheme.md: status updated from Draft to incorporated into
  SEP, removed outdated "MCP Skills Convention" phrasing

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: olaservo

README.md

@@ -102,10 +102,10 @@ This IG may propose becoming a Working Group if:
 | Experimental findings repo | Proposed | Ola | Dedicated repo for implementations and evaluation results |
 | SEP-2076 review | In Progress | Yu Yi | Skills as first-class primitive proposal |
 | Registry skills.json proposal | In Progress | Ozz | Skills metadata in registry schema |
-| MCP Skills Convention v0.1 | Proposed | TBD | Documented pattern (not spec) for skills over existing primitives |
+| Skills Extension SEP | In Review | Peter (@pja-ant) | Extensions Track SEP for `skill://` resource convention ([#75](https://github.com/modelcontextprotocol/experimental-ext-skills/issues/75)); evolved from Convention v0.1 (#43) |
 
 ## Success Criteria
 
 - **Short-term:** Documented consensus on requirements and evaluation of existing approaches
-- **Medium-term:** Clear recommendation (convention vs. protocol extension vs. both)
+- **Medium-term:** Clear recommendation (convention vs. protocol extension vs. both) — the draft [Skills Extension SEP](https://github.com/modelcontextprotocol/experimental-ext-skills/pull/69) represents the IG's current direction: a formal extension using existing Resources primitives
 - **Long-term:** Interoperable skill distribution across MCP servers and clients

docs/approaches.md

@@ -17,6 +17,8 @@ Several design considerations are emerging from community discussion:
 
 The approaches below span a spectrum. At one end, skills become a first-class MCP primitive with dedicated protocol methods (Approach 1). At the other, existing primitives are used with documented conventions (Approach 6). A key question for this IG is whether convention can prove patterns before standardization — or whether the ecosystem needs protocol-level support to achieve reliable interoperability. These are not mutually exclusive; convention work can inform and de-risk a future protocol extension.
 
+**Current status:** The convention approach (Approach 6) was pursued and quickly evolved into a formal Extensions Track SEP ([#69](https://github.com/modelcontextprotocol/experimental-ext-skills/pull/69)), building on convergence across 4+ independent `skill://` implementations. The SEP uses existing Resources primitives with zero protocol changes, positioning it between pure convention and a new primitive. See [#75](https://github.com/modelcontextprotocol/experimental-ext-skills/issues/75) for tracking.
+
 ## 1. Skills as Distinct MCP Primitives
 
 Add Agent Skills as a first-class, discoverable primitive in MCP. A skill is a named bundle of instructions plus references to tools, prompts, and resources that together teach an agent how to perform a domain-specific workflow.
@@ -131,6 +133,8 @@ Use server instructions as a pointer to a resource: "If you need to do X, fetch
 
 ## 6. Official Convention as Intermediate Step
 
+> **Status:** This approach was pursued and graduated into the draft [Skills Extension SEP](https://github.com/modelcontextprotocol/experimental-ext-skills/pull/69) ([#75](https://github.com/modelcontextprotocol/experimental-ext-skills/issues/75)). The SEP formalizes the convention as an Extensions Track specification using existing Resources primitives — zero protocol changes, backward compatible. Content format is delegated to [agentskills.io](https://agentskills.io/specification). The text below is preserved as historical context for how this approach was originally framed.
+
 A documented "MCP Skills Convention" as a middle path between ad-hoc experiments and protocol extension. This could:
 
 - Define well-known URI schemes or naming patterns (e.g., resources matching `**/SKILL.md`). See [Skill URI Scheme Proposal](skill-uri-scheme.md) for a detailed survey and recommendation.
@@ -139,7 +143,7 @@ A documented "MCP Skills Convention" as a middle path between ad-hoc experiments
 - Be documented in MCP docs as a "Pattern" — not in protocol schema, but officially recommended
 - Allow data gathering on adoption before considering protocol-level changes
 
-This mirrors how other ecosystems (e.g., Kubernetes) graduate patterns: start as convention, prove value, then formalize. Could be a concrete IG deliverable: "MCP Skills Convention v0.1."
+This mirrors how other ecosystems (e.g., Kubernetes) graduate patterns: start as convention, prove value, then formalize.
 
 **Advantages of the convention approach:**
 

docs/skill-uri-scheme.md

@@ -3,13 +3,13 @@
 > Proposed convention for identifying skill resources over MCP.
 
 **Issue:** [#44](https://github.com/modelcontextprotocol/experimental-ext-skills/issues/44)
-**Status:** Draft
+**Status:** Incorporated into the draft [Skills Extension SEP](https://github.com/modelcontextprotocol/experimental-ext-skills/pull/69). This survey informed the SEP's URI scheme design; see also [PR #70](https://github.com/modelcontextprotocol/experimental-ext-skills/pull/70) for subsequent refinements (multi-segment paths, path-name decoupling).
 
 ---
 
 ## Summary
 
-This document surveys existing URI patterns for skill resources across implementations, analyzes their trade-offs, and proposes a recommended `skill://` URI scheme for the MCP Skills Convention.
+This document surveys existing URI patterns for skill resources across implementations, analyzes their trade-offs, and proposes a recommended `skill://` URI scheme for skill resources over MCP.
 
 ## Survey of Existing Patterns