docs: add workflows reference, reorganize into docs/reference/, and add --version flag (#2244)

* docs: add workflows reference, reorganize into docs/reference/, and add --version flag

- Move integrations.md, extensions.md, presets.md into docs/reference/
- New docs/reference/workflows.md: command reference for all workflow
  commands, built-in SDD Cycle workflow with Mermaid diagram, step types,
  expressions, input types, state/resume, and FAQ
- Rename workflow input feature_name to spec with prompt 'Describe what
  you want to build' to match speckit.specify command terminology
- Add --version / -V flag to root specify command with tests
- Update docs/toc.yml, README.md links, and docs/upgrade.md cross-reference
  to use reference/ paths
- Add workflow command to README CLI reference table

* docs: update speckit_version requirement to >=0.7.2 in workflow example

workflows/PUBLISHING.md

@@ -62,10 +62,10 @@ requires:
     any: ["claude", "gemini"]      # At least one required
 
 inputs:
-  feature_name:
+  spec:
     type: string
     required: true
-    prompt: "Feature name"
+    prompt: "Describe what you want to build"
   scope:
     type: string
     default: "full"
@@ -75,7 +75,7 @@ steps:
   - id: specify
     command: speckit.specify
     input:
-      args: "{{ inputs.feature_name }}"
+      args: "{{ inputs.spec }}"
 
   - id: review
     type: gate
@@ -99,7 +99,7 @@ steps:
 
 ```bash
 # Run with required inputs
-specify workflow run ./workflow.yml --input feature_name="user-auth"
+specify workflow run ./workflow.yml --input spec="Build a user authentication system with OAuth support"
 
 # Check validation
 specify workflow info ./workflow.yml

workflows/README.md

@@ -11,7 +11,7 @@ steps:
   - id: specify
     command: speckit.specify
     input:
-      args: "{{ inputs.feature_name }}"
+      args: "{{ inputs.spec }}"
 
   - id: review
     type: gate
@@ -35,10 +35,10 @@ specify workflow search
 specify workflow add speckit
 
 # Or run directly from a local YAML file
-specify workflow run ./workflow.yml --input feature_name="user-auth"
+specify workflow run ./workflow.yml --input spec="Build a user authentication system with OAuth support"
 
 # Run an installed workflow with inputs
-specify workflow run speckit --input feature_name="user-auth"
+specify workflow run speckit --input spec="Build a user authentication system with OAuth support"
 
 # Check run status
 specify workflow status
@@ -59,20 +59,20 @@ specify workflow remove speckit
 
 ```bash
 specify workflow add speckit
-specify workflow run speckit --input feature_name="user-auth"
+specify workflow run speckit --input spec="Build a user authentication system with OAuth support"
 ```
 
 ### From a Local YAML File
 
 ```bash
-specify workflow run ./my-workflow.yml --input feature_name="user-auth"
+specify workflow run ./my-workflow.yml --input spec="Build a user authentication system with OAuth support"
 ```
 
 ### Multiple Inputs
 
 ```bash
 specify workflow run speckit \
-  --input feature_name="user-auth" \
+  --input spec="Build a user authentication system with OAuth support" \
   --input scope="backend-only"
 ```
 
@@ -88,7 +88,7 @@ Invoke an installed Spec Kit command by name via the integration CLI:
 - id: specify
   command: speckit.specify
   input:
-    args: "{{ inputs.feature_name }}"
+    args: "{{ inputs.spec }}"
   integration: claude        # Optional: override workflow default
   model: "claude-sonnet-4-20250514"   # Optional: override model
 ```
@@ -225,7 +225,7 @@ Workflow definitions use `{{ expression }}` syntax for dynamic values:
 
 ```yaml
 # Access inputs
-args: "{{ inputs.feature_name }}"
+args: "{{ inputs.spec }}"
 
 # Access previous step outputs
 args: "{{ steps.specify.output.file }}"
@@ -245,10 +245,10 @@ Workflow inputs are type-checked and coerced from CLI string values:
 
 ```yaml
 inputs:
-  feature_name:
+  spec:
     type: string
     required: true
-    prompt: "Feature name"
+    prompt: "Describe what you want to build"
   task_count:
     type: number
     default: 5

workflows/speckit/workflow.yml

@@ -7,15 +7,15 @@ workflow:
   description: "Runs specify → plan → tasks → implement with review gates"
 
 requires:
-  speckit_version: ">=0.6.1"
+  speckit_version: ">=0.7.2"
   integrations:
     any: ["copilot", "claude", "gemini"]
 
 inputs:
-  feature_name:
+  spec:
     type: string
     required: true
-    prompt: "Feature name"
+    prompt: "Describe what you want to build"
   integration:
     type: string
     default: "copilot"
@@ -30,7 +30,7 @@ steps:
     command: speckit.specify
     integration: "{{ inputs.integration }}"
     input:
-      args: "{{ inputs.feature_name }}"
+      args: "{{ inputs.spec }}"
 
   - id: review-spec
     type: gate
@@ -42,7 +42,7 @@ steps:
     command: speckit.plan
     integration: "{{ inputs.integration }}"
     input:
-      args: "{{ inputs.feature_name }}"
+      args: "{{ inputs.spec }}"
 
   - id: review-plan
     type: gate
@@ -54,10 +54,10 @@ steps:
     command: speckit.tasks
     integration: "{{ inputs.integration }}"
     input:
-      args: "{{ inputs.feature_name }}"
+      args: "{{ inputs.spec }}"
 
   - id: implement
     command: speckit.implement
     integration: "{{ inputs.integration }}"
     input:
-      args: "{{ inputs.feature_name }}"
+      args: "{{ inputs.spec }}"