bug: Neovim 0.12 vim.validate deprecation conflicts with 0.10 support

### Did you check docs and existing issues?

- [x] I have read the Grapple docs
- [x] I have searched the existing issues of Grapple

### Neovim version (nvim -v)

NVIM v0.12.0

### Operating system/version

macOS Tahoe 26.4

### Describe the bug

Grapple still uses table-form `vim.validate({ ... })` in runtime code, which triggers deprecation warnings on Neovim 0.12.

The affected call sites are:
- `lua/grapple/scope_manager.lua`
- `lua/grapple/tag_container.lua`
- `lua/grapple/tag_manager.lua`

The problem is that switching those calls directly to positional `vim.validate(name, value, validator, ...)` fixes 0.12, but breaks Neovim 0.10 support.

Tested locally:
- `NVIM v0.10.4`: positional `vim.validate(...)` fails
- `NVIM v0.11.4`: works
- `NVIM v0.12.0`: works, and table-form is deprecated

So there are two valid paths:
1. Raise the minimum supported Neovim version to `0.11`
2. Add a small compatibility wrapper/version check for `vim.validate`

I have working branches for both approaches:
- Drop 0.10 support and switch directly to positional `vim.validate(...)`:
- https://github.com/maxrzaw/grapple.nvim/tree/fix/nvim-0.12-validate-deprecation
- Keep 0.10 support with a small compatibility wrapper:
- https://github.com/maxrzaw/grapple.nvim/tree/fix/nvim-validate-compat

If this sounds reasonable, I can open a PR for either approach.

### Steps To Reproduce

1. Load Grapple on Neovim `0.12.0`
2. Run `:checkhealth vim.deprecated`
3. Observe the `vim.validate({ ... })` deprecation warning

### Expected Behavior

1. Load Grapple on Neovim `0.12.0`
2. Run `:checkhealth vim.deprecated`
3. Do not observe the `vim.validate({ ... })` deprecation warning

### Repro

```Lua
-- DO NOT change the paths
local root = vim.fn.fnamemodify("./.repro", ":p")
for _, name in ipairs({ "config", "data", "state", "cache" }) do
vim.env[("XDG_%s_HOME"):format(name:upper())] = root .. "/" .. name
end
local lazypath = root .. "/plugins/lazy.nvim"
if not vim.loop.fs_stat(lazypath) then
vim.fn.system({
"git",
"clone",
"--filter=blob:none",
"https://github.com/folke/lazy.nvim.git",
lazypath,
})
end
vim.opt.runtimepath:prepend(lazypath)
require("lazy").setup({
{
"cbochs/grapple.nvim",
config = function()
require("grapple").setup()
end,
},
}, {
root = root .. "/plugins",
})
```

Start by reviewing the vim.validate call sites in lua/grapple/scope_manager.lua, lua/grapple/tag_container.lua, and lua/grapple/tag_manager.lua, along with the reported Neovim 0.10–0.12 behavior. Confirm the chosen compatibility approach and run :checkhealth vim.deprecated on Neovim 0.12, plus the supported-version checks. Done means the warning is gone without dropping or unintentionally breaking the stated support range.

Written by the indexing model from the issue text.