Phase E: action-language tool vocabulary

Replace Claude-Code-specific tool names in skill prose, prompt
templates, and OpenCode-facing docs with action-language descriptions
that resolve to each runtime's native tool via the per-platform refs.

Changes by category:

- Prose mentions ("Use TodoWrite to track...", "Use Task tool with
  general-purpose type") → action language ("Track each item as a
  todo", "Dispatch a general-purpose subagent")

- Prompt template headers (6 files): "Task tool (general-purpose):"
  → "Subagent (general-purpose):" — preserves the type information
  without naming Claude Code's specific dispatch tool

- DOT flowchart node labels: "Invoke Skill tool" → "Invoke the
  skill"; "Create TodoWrite todo per item" → "Create a todo per
  item"

- OpenCode INSTALL.md and docs/README.opencode.md: replace the old
  "TodoWrite → todowrite, Task → @mention" mapping (which both
  taught a vocabulary skills no longer use AND was wrong about
  @mention being a real OpenCode syntax) with an action-language
  mapping verified against the installed OpenCode CLI's tool
  inventory.

The platform-tools refs landed in Phase B already document each
runtime's resolution; skills now speak in the actions those refs
map. Tool names that genuinely belong only in the per-platform
dispatch section ("In Claude Code: Use the `Skill` tool") and the
Claude-Code-specific Bash run_in_background flag note in
visual-companion remain — those are intentional carve-outs.

skills/subagent-driven-development/SKILL.md

@@ -57,15 +57,15 @@ digraph process {
         "Dispatch code quality reviewer subagent (./code-quality-reviewer-prompt.md)" [shape=box];
         "Code quality reviewer subagent approves?" [shape=diamond];
         "Implementer subagent fixes quality issues" [shape=box];
-        "Mark task complete in TodoWrite" [shape=box];
+        "Mark task complete in todo list" [shape=box];
     }
 
-    "Read plan, extract all tasks with full text, note context, create TodoWrite" [shape=box];
+    "Read plan, extract all tasks with full text, note context, create todos" [shape=box];
     "More tasks remain?" [shape=diamond];
     "Dispatch final code reviewer subagent for entire implementation" [shape=box];
     "Use superpowers:finishing-a-development-branch" [shape=box style=filled fillcolor=lightgreen];
 
-    "Read plan, extract all tasks with full text, note context, create TodoWrite" -> "Dispatch implementer subagent (./implementer-prompt.md)";
+    "Read plan, extract all tasks with full text, note context, create todos" -> "Dispatch implementer subagent (./implementer-prompt.md)";
     "Dispatch implementer subagent (./implementer-prompt.md)" -> "Implementer subagent asks questions?";
     "Implementer subagent asks questions?" -> "Answer questions, provide context" [label="yes"];
     "Answer questions, provide context" -> "Dispatch implementer subagent (./implementer-prompt.md)";
@@ -78,8 +78,8 @@ digraph process {
     "Dispatch code quality reviewer subagent (./code-quality-reviewer-prompt.md)" -> "Code quality reviewer subagent approves?";
     "Code quality reviewer subagent approves?" -> "Implementer subagent fixes quality issues" [label="no"];
     "Implementer subagent fixes quality issues" -> "Dispatch code quality reviewer subagent (./code-quality-reviewer-prompt.md)" [label="re-review"];
-    "Code quality reviewer subagent approves?" -> "Mark task complete in TodoWrite" [label="yes"];
-    "Mark task complete in TodoWrite" -> "More tasks remain?";
+    "Code quality reviewer subagent approves?" -> "Mark task complete in todo list" [label="yes"];
+    "Mark task complete in todo list" -> "More tasks remain?";
     "More tasks remain?" -> "Dispatch implementer subagent (./implementer-prompt.md)" [label="yes"];
     "More tasks remain?" -> "Dispatch final code reviewer subagent for entire implementation" [label="no"];
     "Dispatch final code reviewer subagent for entire implementation" -> "Use superpowers:finishing-a-development-branch";
@@ -132,7 +132,7 @@ You: I'm using Subagent-Driven Development to execute this plan.
 
 [Read plan file once: docs/superpowers/plans/feature-plan.md]
 [Extract all 5 tasks with full text and context]
-[Create TodoWrite with all tasks]
+[Create todos for all tasks]
 
 Task 1: Hook installation script
 

skills/subagent-driven-development/code-quality-reviewer-prompt.md

@@ -7,7 +7,7 @@ Use this template when dispatching a code quality reviewer subagent.
 **Only dispatch after spec compliance review passes.**
 
 ```
-Task tool (general-purpose):
+Subagent (general-purpose):
   Use template at requesting-code-review/code-reviewer.md
 
   DESCRIPTION: [task summary, from implementer's report]

skills/subagent-driven-development/implementer-prompt.md

@@ -3,7 +3,7 @@
 Use this template when dispatching an implementer subagent.
 
 ```
-Task tool (general-purpose):
+Subagent (general-purpose):
   description: "Implement Task N: [task name]"
   prompt: |
     You are implementing Task N: [task name]

skills/subagent-driven-development/spec-reviewer-prompt.md

@@ -5,7 +5,7 @@ Use this template when dispatching a spec compliance reviewer subagent.
 **Purpose:** Verify implementer built what was requested (nothing more, nothing less)
 
 ```
-Task tool (general-purpose):
+Subagent (general-purpose):
   description: "Review spec compliance for Task N"
   prompt: |
     You are reviewing whether an implementation matches its specification.