feat: add cobra Example fields to all 115+ CLI commands

Every `ctx <command> --help` now shows practical usage examples.
Expanded examples.yaml from 5 add-subtype entries to 136 keys,
wired desc.Example() into all cmd.go files and parent.Cmd(),
and added drift-prevention comments to YAML asset files.

Changes:
- examples.yaml: 136 command-keyed entries, add-subtypes
  namespaced under "add." prefix
- parent.Cmd(): auto-loads Example from desc key
- 115 cmd.go files + bootstrap root: Example field wired
- ForType(): uses ExampleKeyPrefixAdd constant
- TestExamplesYAMLLinkage: validates against desc key constants
- commands.yaml, flags.yaml: update reminder comments

Spec: specs/cli-examples.md
Signed-off-by: Jose Alekhinne <jose@ctx.ist>

Author: josealekhine

.context/TASKS.md

@@ -68,15 +68,21 @@ TASK STATUS LABELS:
 
 ### Phase -3: DevEx
 
-- [ ] Plugin enablement gap: Ref:
+- [x] Plugin enablement gap: Ref:
   `ideas/plugin-enablement-gap.md`. Local-installed plugins get
   registered in `installed_plugins.json` but not auto-added to
   `enabledPlugins`, so slash commands are invisible in non-ctx
   projects.
 
-- [ ] Add cobra Example fields to CLI commands via
+- [x] Add cobra Example fields to CLI commands via
   examples.yaml #added:2026-03-20-163413
 
+- [ ] Add CLI YAML drift detection test: verify flag names in
+  examples.yaml match actual registered flags, and Use: patterns
+  in commands.yaml match Use constants. Structural linkage is
+  already tested; this covers content-level drift. Semantic
+  accuracy (does the description match behavior?) needs periodic
+  LLM audit — not automatable. #priority:medium #added:2026-04-05
 
 - [ ] Create ctx-docstrings skill: audit and fix docstrings
   against CONVENTIONS.md Documentation section. Skill loads

internal/assets/commands/commands.yaml

@@ -1,6 +1,12 @@
 # Command descriptions for ctx CLI.
 # Used by assets.CommandDesc() to populate cobra Short/Long fields.
 # Keys use dot notation: parent.subcommand (e.g., pad.show)
+#
+# UPDATE THIS FILE when command behavior changes (new flags,
+# renamed subcommands, changed semantics). Short/Long text
+# appears in --help output and must stay accurate.
+#
+# See also: examples.yaml (Example fields), flags.yaml (flag descriptions).
 
 add:
   long: |-