docs: clarify Fin and model auto-routing

- Separate model auto-routing from Plan/Agent/YOLO TUI modes across all
  READMEs and docs/MODES.md
- Introduce Fin as the fast thinking-off deepseek-v4-flash seam for
  routing, summaries, RLM child calls, and coordination work
- Document /goal as current session tracking (not a TUI mode), with note
  that a future Goal work surface should stay distinct from --model auto
- Extend deprecation shim timeline from 'one release cycle' to
  through v0.8.x in REBRAND.md and npm READMEs
- Fix selection_to_text test to expect inline thinking preview
  (short completed thinking now renders inline without Ctrl+O
  affordance)

docs/CONFIGURATION.md

@@ -481,7 +481,9 @@ If you are upgrading from older releases:
   - `[snapshots].enabled` (bool, default `true`)
   - `[snapshots].max_age_days` (int, default `7`)
   - snapshots live under `~/.deepseek/snapshots/<project_hash>/<worktree_hash>/.git` and never use the workspace's own `.git` directory
-- `context.*` (optional): append-only Flash seam manager, currently opt-in.
+- `context.*` (optional): append-only Fin seam manager, currently opt-in.
+  Fin is the fast `deepseek-v4-flash` path with thinking off used for
+  coordination work such as routing, summaries, and context maintenance.
   Thresholds use the active request input estimate, not lifetime summed API
   usage:
   - `[context].enabled` (bool, default `false`)

docs/MODES.md

@@ -5,6 +5,10 @@ codewhale has two related concepts:
 - **TUI mode**: what kind of visible interaction you're in (Plan/Agent/YOLO).
 - **Approval mode**: how aggressively the UI asks before executing tools.
 
+Model selection is separate. `--model auto` and `/model auto` route each turn to
+a concrete model and thinking level; they are not TUI modes and are not part of
+the `Tab` cycle.
+
 ## TUI Modes
 
 Press `Tab` to complete composer menus, queue a draft as a next-turn follow-up
@@ -20,6 +24,14 @@ Run `/mode` to open the mode picker, or switch directly with `/mode agent`,
 
 All three modes have access to persistent RLM sessions through `rlm_open`, `rlm_eval`, `rlm_configure`, and `rlm_close`. Inside an RLM Python REPL, `sub_query_batch` fans out 1-16 cheap parallel child calls pinned to `deepseek-v4-flash`. The model reaches for it when work is too large or repetitive for the parent transcript.
 
+The fast `deepseek-v4-flash` / thinking-off path is called Fin in the product
+language. Fin is a seam for routing, summaries, cheap child calls, and
+coordination work; it does not change approval behavior.
+
+`/goal` sets a session objective with an optional token budget. It is goal
+tracking today, not a separate TUI mode. If CodeWhale grows a persistent Goal
+work surface later, it should remain distinct from `--model auto`.
+
 ## Compatibility Notes
 
 - Older settings files with `default_mode = "normal"` still load as `agent`; saving rewrites the normalized value.

docs/REBRAND.md

@@ -62,16 +62,16 @@ Anything that targets the DeepSeek provider API stays exactly as it was:
   will be flipped to the new names in a follow-up.
 - **Docker image**: `ghcr.io/hmbown/codewhale`.
 
-## Deprecation shims (one release cycle)
+## Deprecation shims (through v0.8.x)
 
 To keep existing shell aliases, scripts, and CI working through the rename,
-v0.8.41 ships **deprecation shims** for one cycle:
+v0.8.41 and later v0.8.x releases ship **deprecation shims**:
 
 - A `deepseek` binary that prints a one-line warning to stderr and forwards
   argv to `codewhale`.
 - A `deepseek-tui` binary that does the same for `codewhale-tui`.
-- An `npm` package at `deepseek-tui@0.8.41` with no `bin` and a postinstall
-  that prints a clear "rename" notice.
+- An `npm` package at `deepseek-tui@0.8.x` with no `bin` and a postinstall
+  that prints a clear rename notice.
 
 These shims will be removed in **v0.9.0**. Please migrate before then.