docs(api): move UNIT_SPELLCAST_* events into the Events section, fix TOC link

The TOC entry pointed at #unit_spellcast_-events-player, but the heading
generates #unit_spellcast_-events (no -player suffix) — broken link. Move
both the TOC entry and the content block out of the Spell section and into
the Events section where the other event docs live, and correct the anchor.

Author: brues-code

docs/API.md

@@ -131,6 +131,7 @@ build instructions.
   - [`UNIT_FACTION` event (fire-coverage fix)](#unit_faction-event-fire-coverage-fix)
   - [`UPDATE_MOUSEOVER_UNIT` event (loss-fire fix)](#update_mouseover_unit-event-loss-fire-fix)
   - [`UPDATE_SHAPESHIFT_FORM` event](#update_shapeshift_form-event)
+  - [`UNIT_SPELLCAST_*` events](#unit_spellcast_-events)
 
 - [Expansion](#expansion)
   - [`GetClassicExpansionLevel()`](#getclassicexpansionlevel)
@@ -461,7 +462,6 @@ build instructions.
   - [`C_Spell.CancelSpellByID(spellID)` / `CancelSpellByName(name)`](#c_spellcancelspellbyidspellid--cancelspellbynamename)
   - [`C_Spell.UnitCastingInfo(unit)` / `C_Spell.CastingInfo()`](#c_spellunitcastinginfounit--c_spellcastinginfo)
   - [`C_Spell.UnitChannelInfo(unit)` / `C_Spell.ChannelInfo()`](#c_spellunitchannelinfounit--c_spellchannelinfo)
-  - [`UNIT_SPELLCAST_*` events (player)](#unit_spellcast_-events-player)
   - [`C_Spell.GetSpellLevelInfo(spellID)`](#c_spellgetspelllevelinfospellid)
   - [`GetSpellRequiredTargetLevel(spellID)`](#getspellrequiredtargetlevelspellid)
 
@@ -3244,6 +3244,131 @@ The cached "last form" sentinel uses `-1` for "player descriptor not
 yet resolvable" so transient resolution failures during early login
 don't get misread as leaving a form.
 
+### `UNIT_SPELLCAST_*` events
+
+Backport of the TBC+ cast/channel events to 1.12, for the **local player and
+other units**. Ported cast-bar / rotation addons (anything written against
+the modern signature) register these instead of vanilla's arg-less
+`SPELLCAST_*` events and read `unit, castGUID, spellID` directly. Thirteen
+events are provided; six also fire for non-player units:
+
+| Event | Fires when | Units | Args |
+|-------|-----------|-------|------|
+| `UNIT_SPELLCAST_SENT` | `CMSG_CAST_SPELL` leaves the client (earliest point) | player | `unit, target, castGUID, spellID, spellName, rank` |
+| `UNIT_SPELLCAST_START` | a cast-time spell begins | all | `unit, castGUID, spellID, spellName, rank` |
+| `UNIT_SPELLCAST_STOP` | a cast-time spell ends (any reason) | all | same |
+| `UNIT_SPELLCAST_DELAYED` | pushback extends the cast | player | same |
+| `UNIT_SPELLCAST_SUCCEEDED` | the spell goes off (`SMSG_SPELL_GO`) — incl. instants | all | same |
+| `UNIT_SPELLCAST_INTERRUPTED` | a started **cast** is interrupted (kick, movement, LoS) — never for channels | all | same |
+| `UNIT_SPELLCAST_FAILED` | a cast is rejected before it starts (range, mana, cooldown) with an error shown | player | same |
+| `UNIT_SPELLCAST_FAILED_QUIET` | a cast fails with **no** error shown (spammy retry, reticle cancel, …) | player | same |
+| `UNIT_SPELLCAST_CHANNEL_START` | a channel begins | all | same |
+| `UNIT_SPELLCAST_CHANNEL_UPDATE` | pushback shortens a channel | player | same |
+| `UNIT_SPELLCAST_CHANNEL_STOP` | a channel ends | all | same |
+| `UNIT_SPELLCAST_RETICLE_TARGET` | a ground-target reticle appears (AoE placement — Blizzard, Flare, …) | player | `unit, "", spellID, spellName, rank` |
+| `UNIT_SPELLCAST_RETICLE_CLEAR` | the reticle is placed or cancelled | player | `unit, "", spellID, spellName, rank` |
+
+`unit` (arg1) is the token of the casting unit — `"player"` for your own
+casts, or a unit token (`"target"`, `"focus"`, `"party3"`, `"nameplate2"`,
+`"pet"`, `"mouseover"`, …) for another unit. `spellName` / `rank` are
+ClassicAPI tail extensions (modern stops at `spellID`); addons reading only
+the first three positional args are unaffected.
+
+**Per-token fan-out.** A caster GUID can map to several tokens at once (your
+`target` is also `party2` and `nameplate1`). Like retail, the event fires
+**once per token** currently pointing at the caster, so a `target`-frame
+cast bar, a `party2` frame, and a nameplate cast bar each get their own
+event with the same castGUID. Tokens are resolved fresh at fire time (they
+shift frame-to-frame). If you run **SuperWoW**, its raw-GUID token (`"0x…"`)
+is deliberately filtered out — only standard tokens are fanned out.
+
+**Non-player limits.** Only the six events above fire for other units, and
+they're **best-effort** — driven purely by the packets an observer receives:
+- `SENT` never fires (only your own outgoing casts are visible).
+- `DELAYED` / `CHANNEL_UPDATE` never fire (pushback is sent only to the
+  caster, so another unit's bar can't stretch/shrink from damage).
+- `FAILED` never fires (a pre-cast requirement failure is client-local).
+- A remote cast/channel only has timing from the moment its
+  `SMSG_SPELL_START` was observed; casters who were already casting when
+  they came into range have no start time.
+
+**Channels never fire `INTERRUPTED`.** Retail emits only `CHANNEL_STOP` when a
+channel ends, whether it completed or was cut short (verified against retail),
+so ClassicAPI matches that for both the player and other units. `INTERRUPTED`
+is a cast-only event.
+
+**Reticle events** fire for ground-targeted (AoE) spells only, always for the
+player: `RETICLE_TARGET` when the placement reticle comes up, `RETICLE_CLEAR`
+when it's placed or cancelled. There's no cast yet, so the castGUID slot
+(arg2) is empty — retail pushes `nil` there, but the engine's event
+dispatcher can't emit a `nil` mid-argument-list, so ClassicAPI pushes `""`
+instead. `unit` (arg1) and `spellID` (arg3) are exact; arg2 is the only
+difference and is inconsequential for a reticle.
+
+**castGUID.** A synthesized string in the modern shape
+`Cast-<type>-<serverID>-<instanceID>-<zoneUID>-<spellID>-<castUID>`. Vanilla
+can't know server / instance / zone, so those three fields are `0`; the
+load-bearing parts are the `spellID` (field 6, which addons `strsplit("-")`
+out) and a unique-per-cast `castUID` (field 7). **Every event of one cast
+carries the same castGUID**, so `SENT` → `START`/`CHANNEL_START` →
+`SUCCEEDED` → `STOP`/`CHANNEL_STOP` all pair up — including across the caster
+and observers (they converge on the same value), and a chained same-spell
+recast gets its own castUID. The `type` and `castUID` follow the
+[spell-cast-GUID spec](https://warcraft.wiki.gg/wiki/GUID#Cast):
+- **Type 3** (real casts — the common case): `castUID` is time-based — the
+  low 23 bits are the cast's UNIX-epoch second, the higher bits a per-second
+  counter.
+- **Type 2** (`UNIT_SPELLCAST_FAILED` — a local-only cast that never reached
+  the server): `castUID` is a plain locally-incrementing integer.
+
+**Ordering** matches modern:
+
+- Cast-time spell: `SENT → START → SUCCEEDED → STOP`.
+- Channel: `SENT → CHANNEL_START → SUCCEEDED → CHANNEL_STOP` (CHANNEL_START
+  before SUCCEEDED, as on retail).
+- Instant: `SENT → SUCCEEDED`.
+
+**INTERRUPTED vs FAILED vs FAILED_QUIET** follow modern's split: a spell that
+never started (out of range, not enough mana, on cooldown, LoS to a target)
+fires `FAILED`, except for a fixed whitelist of "quiet" `SpellCastResult`
+codes that fire `FAILED_QUIET` instead — `SPELL_IN_PROGRESS` (casting while
+already casting / a spell-queue rejection), `DONT_REPORT` (fake fails, a
+cancelled ground reticle), and `CHARMED`. That whitelist mirrors the 3.3.5
+client's own unit-spellcast dispatch, mapped to vanilla's `SpellCastResult`
+enum. A spell that was *already casting* and gets stopped (an enemy kick,
+moving to cancel, breaking LoS mid-cast) fires `INTERRUPTED`. Holding
+the cast key while running fires `INTERRUPTED` repeatedly (once per retry),
+each reusing the interrupted cast's castGUID — matching retail.
+
+**Channel pushback (player).** Taking damage while channeling shortens the
+channel in vanilla; `CHANNEL_UPDATE` fires on each hit and
+[`C_Spell.UnitChannelInfo`](#c_spellunitchannelinfounit--c_spellchannelinfo)'s
+`endTimeMs` re-anchors to the server's new remaining time, so cast bars
+shrink correctly. (The event carries no time — like retail it's a "re-read
+now" trigger; timing is read back from `UnitChannelInfo`.)
+
+Every fire is gated on whether any frame is registered for that event, so
+the whole system costs one pointer-compare per state transition when no
+addon uses it (no arg synthesis, no DBC lookups, no per-token fan-out).
+
+```lua
+local f = CreateFrame("Frame")
+for _, e in ipairs({
+    "UNIT_SPELLCAST_START", "UNIT_SPELLCAST_STOP",
+    "UNIT_SPELLCAST_SUCCEEDED", "UNIT_SPELLCAST_CHANNEL_START",
+}) do f:RegisterEvent(e) end
+f:SetScript("OnEvent", function()
+    -- vanilla passes event/arg1/... as globals, not function params
+    if arg1 == "target" then print(event, arg3) end  -- arg3 = spellID
+end)
+```
+
+> **Additive to the vanilla `SPELLCAST_*` events.** The engine's own arg-less
+> `SPELLCAST_START` / `SPELLCAST_CHANNEL_UPDATE` / … still fire as before;
+> these `UNIT_`-prefixed events are the modern layer on top. The empowered-cast
+> events (`UNIT_SPELLCAST_EMPOWER_*`, a Dragonflight addition) are not
+> implemented — vanilla has no empowered casts.
+
 ## Expansion
 
 Helpers shipped by modern Classic Era / Cata Classic for addons that
@@ -11486,131 +11611,6 @@ otherwise it falls back to `name`/`displayName`/`textureID`/`spellID` with
 **`nil` times**. The player path is unchanged (full timing). Same
 placeholder fields as `C_Spell.UnitCastingInfo`.
 
-### `UNIT_SPELLCAST_*` events
-
-Backport of the TBC+ cast/channel events to 1.12, for the **local player and
-other units**. Ported cast-bar / rotation addons (anything written against
-the modern signature) register these instead of vanilla's arg-less
-`SPELLCAST_*` events and read `unit, castGUID, spellID` directly. Thirteen
-events are provided; six also fire for non-player units:
-
-| Event | Fires when | Units | Args |
-|-------|-----------|-------|------|
-| `UNIT_SPELLCAST_SENT` | `CMSG_CAST_SPELL` leaves the client (earliest point) | player | `unit, target, castGUID, spellID, spellName, rank` |
-| `UNIT_SPELLCAST_START` | a cast-time spell begins | all | `unit, castGUID, spellID, spellName, rank` |
-| `UNIT_SPELLCAST_STOP` | a cast-time spell ends (any reason) | all | same |
-| `UNIT_SPELLCAST_DELAYED` | pushback extends the cast | player | same |
-| `UNIT_SPELLCAST_SUCCEEDED` | the spell goes off (`SMSG_SPELL_GO`) — incl. instants | all | same |
-| `UNIT_SPELLCAST_INTERRUPTED` | a started **cast** is interrupted (kick, movement, LoS) — never for channels | all | same |
-| `UNIT_SPELLCAST_FAILED` | a cast is rejected before it starts (range, mana, cooldown) with an error shown | player | same |
-| `UNIT_SPELLCAST_FAILED_QUIET` | a cast fails with **no** error shown (spammy retry, reticle cancel, …) | player | same |
-| `UNIT_SPELLCAST_CHANNEL_START` | a channel begins | all | same |
-| `UNIT_SPELLCAST_CHANNEL_UPDATE` | pushback shortens a channel | player | same |
-| `UNIT_SPELLCAST_CHANNEL_STOP` | a channel ends | all | same |
-| `UNIT_SPELLCAST_RETICLE_TARGET` | a ground-target reticle appears (AoE placement — Blizzard, Flare, …) | player | `unit, "", spellID, spellName, rank` |
-| `UNIT_SPELLCAST_RETICLE_CLEAR` | the reticle is placed or cancelled | player | `unit, "", spellID, spellName, rank` |
-
-`unit` (arg1) is the token of the casting unit — `"player"` for your own
-casts, or a unit token (`"target"`, `"focus"`, `"party3"`, `"nameplate2"`,
-`"pet"`, `"mouseover"`, …) for another unit. `spellName` / `rank` are
-ClassicAPI tail extensions (modern stops at `spellID`); addons reading only
-the first three positional args are unaffected.
-
-**Per-token fan-out.** A caster GUID can map to several tokens at once (your
-`target` is also `party2` and `nameplate1`). Like retail, the event fires
-**once per token** currently pointing at the caster, so a `target`-frame
-cast bar, a `party2` frame, and a nameplate cast bar each get their own
-event with the same castGUID. Tokens are resolved fresh at fire time (they
-shift frame-to-frame). If you run **SuperWoW**, its raw-GUID token (`"0x…"`)
-is deliberately filtered out — only standard tokens are fanned out.
-
-**Non-player limits.** Only the six events above fire for other units, and
-they're **best-effort** — driven purely by the packets an observer receives:
-- `SENT` never fires (only your own outgoing casts are visible).
-- `DELAYED` / `CHANNEL_UPDATE` never fire (pushback is sent only to the
-  caster, so another unit's bar can't stretch/shrink from damage).
-- `FAILED` never fires (a pre-cast requirement failure is client-local).
-- A remote cast/channel only has timing from the moment its
-  `SMSG_SPELL_START` was observed; casters who were already casting when
-  they came into range have no start time.
-
-**Channels never fire `INTERRUPTED`.** Retail emits only `CHANNEL_STOP` when a
-channel ends, whether it completed or was cut short (verified against retail),
-so ClassicAPI matches that for both the player and other units. `INTERRUPTED`
-is a cast-only event.
-
-**Reticle events** fire for ground-targeted (AoE) spells only, always for the
-player: `RETICLE_TARGET` when the placement reticle comes up, `RETICLE_CLEAR`
-when it's placed or cancelled. There's no cast yet, so the castGUID slot
-(arg2) is empty — retail pushes `nil` there, but the engine's event
-dispatcher can't emit a `nil` mid-argument-list, so ClassicAPI pushes `""`
-instead. `unit` (arg1) and `spellID` (arg3) are exact; arg2 is the only
-difference and is inconsequential for a reticle.
-
-**castGUID.** A synthesized string in the modern shape
-`Cast-<type>-<serverID>-<instanceID>-<zoneUID>-<spellID>-<castUID>`. Vanilla
-can't know server / instance / zone, so those three fields are `0`; the
-load-bearing parts are the `spellID` (field 6, which addons `strsplit("-")`
-out) and a unique-per-cast `castUID` (field 7). **Every event of one cast
-carries the same castGUID**, so `SENT` → `START`/`CHANNEL_START` →
-`SUCCEEDED` → `STOP`/`CHANNEL_STOP` all pair up — including across the caster
-and observers (they converge on the same value), and a chained same-spell
-recast gets its own castUID. The `type` and `castUID` follow the
-[spell-cast-GUID spec](https://warcraft.wiki.gg/wiki/GUID#Cast):
-- **Type 3** (real casts — the common case): `castUID` is time-based — the
-  low 23 bits are the cast's UNIX-epoch second, the higher bits a per-second
-  counter.
-- **Type 2** (`UNIT_SPELLCAST_FAILED` — a local-only cast that never reached
-  the server): `castUID` is a plain locally-incrementing integer.
-
-**Ordering** matches modern:
-
-- Cast-time spell: `SENT → START → SUCCEEDED → STOP`.
-- Channel: `SENT → CHANNEL_START → SUCCEEDED → CHANNEL_STOP` (CHANNEL_START
-  before SUCCEEDED, as on retail).
-- Instant: `SENT → SUCCEEDED`.
-
-**INTERRUPTED vs FAILED vs FAILED_QUIET** follow modern's split: a spell that
-never started (out of range, not enough mana, on cooldown, LoS to a target)
-fires `FAILED`, except for a fixed whitelist of "quiet" `SpellCastResult`
-codes that fire `FAILED_QUIET` instead — `SPELL_IN_PROGRESS` (casting while
-already casting / a spell-queue rejection), `DONT_REPORT` (fake fails, a
-cancelled ground reticle), and `CHARMED`. That whitelist mirrors the 3.3.5
-client's own unit-spellcast dispatch, mapped to vanilla's `SpellCastResult`
-enum. A spell that was *already casting* and gets stopped (an enemy kick,
-moving to cancel, breaking LoS mid-cast) fires `INTERRUPTED`. Holding
-the cast key while running fires `INTERRUPTED` repeatedly (once per retry),
-each reusing the interrupted cast's castGUID — matching retail.
-
-**Channel pushback (player).** Taking damage while channeling shortens the
-channel in vanilla; `CHANNEL_UPDATE` fires on each hit and
-[`C_Spell.UnitChannelInfo`](#c_spellunitchannelinfounit--c_spellchannelinfo)'s
-`endTimeMs` re-anchors to the server's new remaining time, so cast bars
-shrink correctly. (The event carries no time — like retail it's a "re-read
-now" trigger; timing is read back from `UnitChannelInfo`.)
-
-Every fire is gated on whether any frame is registered for that event, so
-the whole system costs one pointer-compare per state transition when no
-addon uses it (no arg synthesis, no DBC lookups, no per-token fan-out).
-
-```lua
-local f = CreateFrame("Frame")
-for _, e in ipairs({
-    "UNIT_SPELLCAST_START", "UNIT_SPELLCAST_STOP",
-    "UNIT_SPELLCAST_SUCCEEDED", "UNIT_SPELLCAST_CHANNEL_START",
-}) do f:RegisterEvent(e) end
-f:SetScript("OnEvent", function()
-    -- vanilla passes event/arg1/... as globals, not function params
-    if arg1 == "target" then print(event, arg3) end  -- arg3 = spellID
-end)
-```
-
-> **Additive to the vanilla `SPELLCAST_*` events.** The engine's own arg-less
-> `SPELLCAST_START` / `SPELLCAST_CHANNEL_UPDATE` / … still fire as before;
-> these `UNIT_`-prefixed events are the modern layer on top. The empowered-cast
-> events (`UNIT_SPELLCAST_EMPOWER_*`, a Dragonflight addition) are not
-> implemented — vanilla has no empowered casts.
-
 ### `C_Spell.GetSpellLevelInfo(spellID)`
 
 Returns the raw `Spell.dbc` level fields for a spell: