## MODIFIED Requirements
### Requirement: Agents can write files in existing projects
Meeting Assistant SHALL expose a `write_projectfile` tool that can create or update files inside an existing project folder.

The target project SHALL be an existing direct subfolder of the configured projects folder. The target file path SHALL stay inside that project folder.

When no line edit arguments are supplied and `replace_file` is not true, `write_projectfile` SHALL append the supplied content to the file and SHALL create the file when it does not exist.

When `replace_file` is true, `write_projectfile` SHALL replace the whole file with the supplied content.

When both `from` and `to` are supplied, `write_projectfile` SHALL replace the inclusive 1-based line range with the supplied content.

When `insert` is supplied, `write_projectfile` SHALL insert the supplied content at that 1-based line position.

Meeting Assistant SHALL refuse ambiguous writes that combine `replace_file` with line edit arguments.

#### Scenario: Project file is appended or created
- **WHEN** the agent writes a project file without line edit arguments
- **THEN** Meeting Assistant appends the supplied content to an existing file
- **AND** creates the file with the supplied content when it does not exist

#### Scenario: Project file is explicitly replaced
- **WHEN** the agent writes a project file with `replace_file` set to true
- **THEN** Meeting Assistant writes the supplied content as the complete file content

#### Scenario: Project file line range is replaced
- **WHEN** the agent writes a project file with `from` and `to` line numbers
- **THEN** Meeting Assistant replaces the inclusive line range with the supplied content

#### Scenario: Project file content is inserted
- **WHEN** the agent writes a project file with an `insert` line number
- **THEN** Meeting Assistant inserts the supplied content at that line position

#### Scenario: Project file write target is invalid
- **WHEN** the target project is missing or the target path escapes the project folder
- **THEN** Meeting Assistant refuses the project file write

#### Scenario: Project file write mode is ambiguous
- **WHEN** the agent combines `replace_file` with `from`, `to`, or `insert`
- **THEN** Meeting Assistant refuses the project file write