feat(privacy): add DO_NOT_TRACK and DISABLE_TELEMETRY env vars under C3 privacy

docs/manual/08-components-reference/03-c3-key-and-environment-overrides.md

@@ -24,6 +24,8 @@ all of them.
     Catppuccin colors         30+ fish_color_* variables set to Mocha palette
     FZF_DEFAULT_OPTS          FZF themed to Catppuccin Mocha colors
     Right prompt              fish_right_prompt: exit code (on failure) + dim timestamp; always rendered; Docker context added when starship+C3 active
+    DO_NOT_TRACK=1            Universal telemetry opt-out for tools and AI agents
+    DISABLE_TELEMETRY=1       Telemetry opt-out for telemetry-aware CLIs
 
 The bang-bang system spans `key_bindings.fish`, `abbr.fish`, `puffer.fish`, and
 six `expand_bang_*.fish` functions. All are gated together — disabling C3
@@ -35,7 +37,7 @@ is independently controlled by C5 (see below).
 
 ## Sub-categories
 
-`__fish_config_op_overrides` sub-divides into three sub-categories, each
+`__fish_config_op_overrides` sub-divides into four sub-categories, each
 with its own `__fish_config_op_overrides_<slug>` toggle:
 
 ## key-bindings
@@ -53,3 +55,8 @@ Starship, the right prompt, Catppuccin syntax/prompt colors, and FZF
 theming (`$FZF_DEFAULT_OPTS`) -- all driven by the same guard as a single
 unit, not independently toggleable from each other.
 
+## privacy
+
+`$DO_NOT_TRACK` and `$DISABLE_TELEMETRY` environment variables for
+telemetry opt-out across CLI tools, runtimes, and AI agents.
+