feat: Add self-descriptive metadata and fix command format

## Changes

### 1. Added MetaSpec Self-Metadata (pyproject.toml)

Added [tool.metaspec] section to demonstrate metadata format:

**Content**:
- generated_by: "0.9.7"
- domain: "meta-specification"
- lifecycle: "greenfield"
- cli_commands: ["init", "search", "install", "contribute", "list", "info"] (6)
- sd_type: ["sds", "sdd"] (mixed system)
- slash_commands: 19 total (8 SDS + 8 SDD + 3 Evolution)

**Benefits**:
- ✅ MetaSpec describes its own capabilities
- ✅ Serves as reference implementation
- ✅ Demonstrates mixed command system metadata
- ✅ Shows proper command format

### 2. Fixed Command Format (metaspec-metadata-examples.md)

Corrected slash command format in Example 3:

**Before** (incomplete):
- `sds.specify`, `sdd.specify`
- `proposal`, `apply`, `archive`

**After** (complete with prefix):
- `metaspec.sds.specify`, `metaspec.sdd.specify`
- `metaspec.evolution.proposal`, `metaspec.evolution.apply`, `metaspec.evolution.archive`

**Rule**: All MetaSpec commands must include `metaspec.` prefix

## Verification

Confirmed actual command files in marketing-spec-kit:
- ✅ `metaspec.sds.*` (8 files)
- ✅ `metaspec.sdd.*` (8 files)
- ✅ `metaspec.evolution.*` (3 files)

## Impact

- MetaSpec now self-documents its 19 slash commands
- Example 3 shows correct command format
- Other speckits can follow this pattern

Author: NeilJo-GY

docs/metaspec-metadata-examples.md

@@ -87,11 +87,11 @@ sd_type = ["sds", "sdd"]
 
 # Deployed slash commands (19 total)
 slash_commands = [
-    "sds.specify", "sds.plan", "sds.tasks", "sds.implement",
-    "sds.clarify", "sds.analyze", "sds.checklist", "sds.constitution",
-    "sdd.specify", "sdd.plan", "sdd.tasks", "sdd.implement",
-    "sdd.clarify", "sdd.analyze", "sdd.checklist", "sdd.constitution",
-    "proposal", "apply", "archive"
+    "metaspec.sds.specify", "metaspec.sds.plan", "metaspec.sds.tasks", "metaspec.sds.implement",
+    "metaspec.sds.clarify", "metaspec.sds.analyze", "metaspec.sds.checklist", "metaspec.sds.constitution",
+    "metaspec.sdd.specify", "metaspec.sdd.plan", "metaspec.sdd.tasks", "metaspec.sdd.implement",
+    "metaspec.sdd.clarify", "metaspec.sdd.analyze", "metaspec.sdd.checklist", "metaspec.sdd.constitution",
+    "metaspec.evolution.proposal", "metaspec.evolution.apply", "metaspec.evolution.archive"
 ]
 ```
 

pyproject.toml

@@ -206,3 +206,41 @@ exclude_lines = [
     "@abstractmethod",
 ]
 
+[tool.metaspec]
+# MetaSpec metadata - self-descriptive capabilities
+generated_by = "0.9.7"
+domain = "meta-specification"
+lifecycle = "greenfield"
+
+# CLI commands this framework provides
+cli_commands = ["init", "search", "install", "contribute", "list", "info"]
+
+# Mixed command system: SDS (specification) + SDD (development)
+sd_type = ["sds", "sdd"]
+
+# Slash commands for AI-assisted speckit development (19 total)
+slash_commands = [
+    # SDS: Spec-Driven Specification (8 commands)
+    "metaspec.sds.constitution",
+    "metaspec.sds.specify",
+    "metaspec.sds.clarify",
+    "metaspec.sds.plan",
+    "metaspec.sds.tasks",
+    "metaspec.sds.analyze",
+    "metaspec.sds.implement",
+    "metaspec.sds.checklist",
+    # SDD: Spec-Driven Development (8 commands)
+    "metaspec.sdd.constitution",
+    "metaspec.sdd.specify",
+    "metaspec.sdd.clarify",
+    "metaspec.sdd.plan",
+    "metaspec.sdd.checklist",
+    "metaspec.sdd.tasks",
+    "metaspec.sdd.analyze",
+    "metaspec.sdd.implement",
+    # Evolution: Change Management (3 commands)
+    "metaspec.evolution.proposal",
+    "metaspec.evolution.apply",
+    "metaspec.evolution.archive",
+]
+