fix(docs): correct fabricated API/behavior claims in the locks docs

docs/API.md's Locks section described a timeoutMs request param, a
408-timeout response, and field names (acquiredAt/acquiredMs) that
don't exist anywhere in the actual routes.js — the server is single-shot
and never blocks; timing out is a CLI-only concept. Also fixes the
section being spliced into the middle of the pre-existing Sessions
heading and its content.

docs/LANES.md said the owner file stores an epoch in milliseconds
(it's seconds), that the CLI polls every ~1s (it's ~2s), that the lane
card shows a "waiting" state (no such server-side concept exists, only
who currently holds), and included a fabricated "manually transfer a
lock's holder identity" procedure that also contradicted the
never-touch-the-lock-directory etiquette rule stated right above it.

docs/LANES.md

@@ -830,17 +830,16 @@ curl -X POST http://localhost:4820/api/lanes/5/remove \
 
 **Actions gated behind confirmation:** `remove` requires the `confirm` flag to prevent accidental deletion.
 
-
 ## Cross-lane named locks
 
 Cross-lane named locks serialize work that thrashes a shared machine — builds, e2e runs, database migrations — across all lanes, not just within one lane. This is a separate axis from `withLaneLock`, the in-process per-lane lock in `server/lib/lane-lock.js`: `lane-lock` is about _when_ a lane runs internal operations; `named-lock` is about which _other lanes_ must wait.
 
 ### How they work
 
-- **Atomicity via `mkdir`.** Lock ownership is declared via an `owner` marker file in the lock directory. `mkdir` atomically creates or fails with `EEXIST` — no race between check and create.
-- **Holder file format:** `<lock-name>` is owned by a holder string (defaults to `lane<slot>` for the calling lane) that writes `LANES_ROOT/.locks/<lock-name>/owner`. The format is `<holder> <acquired-epoch-ms>` — the holder identity and a timestamp. When a new acquire finds the directory already exists but the holder is stale (more than `LOCK_MAX_HOLD` seconds old, default 2700s / 45 minutes), the old holder is considered dead and the directory is removed before acquiring.
-- **The `LOCK_MAX_HOLD` floor.** The default is 2700 seconds, but it has a **hard floor of 300 seconds**. No caller can force-break a live holder by setting `LOCK_MAX_HOLD=1` — the floor prevents that mistake. The lowest possible timeout is 300 seconds, even if `LOCK_MAX_HOLD` is overridden to something smaller.
-- **Waiting and polling.** `ccam lock acquire` blocks the calling lane (polling the filesystem every ~1 second) until the lock is free or the `--timeout` expires. While waiting, the caller heartbeats its own presence at ~60-second intervals, so a waiting lane never reads as stalled. This means the CLI owns the polling loop — the server is stateless and does not queue or defer — which keeps CCAM's primitives non-orchestrating.
+- **Atomicity via `mkdir`.** Lock ownership is declared via an `owner` marker file inside `LANES_ROOT/.locks/<lock-name>/`. `mkdir` atomically creates the lock directory or fails with `EEXIST` — no race between check and create.
+- **Owner file format:** `<holder> <acquired-epoch-seconds>` — the holder identity (defaults to `lane<slot>` for the calling lane) and a Unix **seconds** timestamp. When a new acquire finds the directory already exists but the holder is stale (older than `LOCK_MAX_HOLD` seconds, default 2700s / 45 minutes), the old holder is considered dead, its directory is removed, and the acquire is retried once before answering.
+- **The `LOCK_MAX_HOLD` floor.** The default is 2700 seconds, but it has a **hard floor of 300 seconds**. No caller can force-break a live holder by setting `LOCK_MAX_HOLD=1` — the floor prevents that mistake. The lowest possible break threshold is 300 seconds, even if `LOCK_MAX_HOLD` is overridden to something smaller.
+- **Waiting and polling.** `ccam lock acquire` blocks the calling lane (polling the server every ~2 seconds via a single-shot `POST /:name/acquire` — the server itself never blocks or queues) until the lock is free or `--timeout` expires. While waiting, it prints a status line every ~60 seconds, so a long wait reads as "still waiting", not a hung command — this is terminal output for whoever is watching, not a dashboard liveness signal.
 
 ### The CLI
 
@@ -861,15 +860,16 @@ Release a lock. Refused with status `409` if the `--holder` does not match the c
 
 ### The lane card
 
-The lane card displays a lock badge when the lane is waiting for or holding a named lock. The badge is polled every 30 seconds (the same interval as git facts and runtime facts), so you see the lock status without a page refresh.
+The lane card shows a lock badge when the lane **holds** a named lock (its `lane<slot>` identity matches a held lock's `holder`) — polled every 30 seconds, the same interval as git and runtime facts. There is no server-side concept of "who is waiting" to display; only who currently holds.
 
 ### Etiquette
 
 **Waiting is normal.** A lane that sits at a lock for a few minutes while another finishes a build is expected behavior, not a failure. Do not interrupt or force-break a lock.
 
 - **Never kill a holder.** If a lane is stuck holding a lock, do not kill the process or the dashboard. Investigate why the holder is not releasing it.
-- **Never delete the lock directory by hand.** If a lock persists after the processes that held it are gone (e.g., after a hard reboot), let `LOCK_MAX_HOLD` and the staleness detection clean it up naturally. If the wait cannot survive that long, the holder string can be changed in a new `acquire` call — a lane that was `lane3` can be manually transferred to `lane5` by a human operator reading the owner file and calling `acquire --holder lane5`, but this is last-resort only.
+- **Never delete the lock directory by hand.** A lock that outlives its holder (e.g. after a hard reboot) is cleaned up automatically — the next `acquire` on that name finds it stale (older than `LOCK_MAX_HOLD`) and breaks it. Deleting `LANES_ROOT/.locks/<name>/` yourself only races whoever else's `acquire` is about to do the same check safely.
 - **Never shrink `LOCK_MAX_HOLD` to force through a wait.** The 300-second floor exists specifically to stop this mistake. If the true holder is gone, the 300-second minimum wait is the price of safety. If the true holder is still running (e.g., a build with a network stall), shortening the timeout from 2700 to 300 does not help — it converts a slow success into a premature timeout, leaving the lock held and every other lane blocked forever.
+
 ## Orchestration: what CCAM does NOT do
 
 **CCAM does not chain, queue, retry, or evaluate gates.**